Definition of duplex in English:



  • 1North American A residential building divided into two apartments.

    • ‘In most suburban communities, it's against the law to build apartment buildings, it's against the law to build duplexes, it's against the law to have small lots.’
    • ‘The Thompsons lived in Langley for a short time, then bought an old house on Lonsdale Avenue and restored it into a duplex.’
    • ‘Council modified its original motion to allow for demolition and the construction of single unit buildings and duplexes.’
    • ‘On one street, I was told that every other house was a duplex that hosted students, neither registered as lodging nor paying fees.’
    • ‘They own a duplex and live in the bottom half, and the recent tenants were also loud, but due to the rent bureau there, there is absolutely no way for them to get rid of the tenants (unless a family member wants to move in, or they sell the place).’
    • ‘According to a preliminary report, nine lots in the area range in width from 22 to 28 feet, house a single family home, could hold a secondary suite and provide density similar to duplexes.’
    • ‘We entered a search for apartments / duplexes costing up to €600,000.’
    • ‘Both apartments and duplexes have a generous electrical specification.’
    • ‘It notes that three-bed semi-detached houses are on the wane in Dublin, being replaced by smaller two-bed duplexes, townhouses and apartments.’
    • ‘At 15 she qualified to live by herself under state care, and it was while she was living in a Surrey duplex that she was impregnated.’
    • ‘Apartments and duplexes became the norm rather than the exception, much to the delight of rookie buyers and older couples trading down.’
    • ‘Within five minutes they pulled up in front of a blue and white duplex, surrounded by several more identical duplexes.’
    • ‘The property has full planning permission for 30 residential units comprising six three-bedroom townhouses, 12 two-bedroom duplexes and 12 one-bedroom apartments.’
    • ‘By the end of this year, Pangnirtung will have also received 11 social housing units, both duplexes and single dwellings.’
    • ‘Four miles from the city centre, Heath Square comprises 72 apartments, duplexes and showhouses.’
    • ‘The Calgary Women Building a Legacy project will hold a ground blessing ceremony on May 5 at an Ogden site that will see the construction of a duplex for two working families living on incomes that fall below the poverty line.’
    • ‘Typically first time buyers are purchasing two-bedroom houses or one to two-bedroom apartments and duplexes in these areas.’
    • ‘My grandparents have been trying to sell their duplex for about 7 months now.’
    • ‘In the city centre, apartments and duplexes saw healthy investor activity due to the tax incentives in operation.’
    • ‘First-time buyers are now moving to the commuter belt in bigger numbers, or else changing their lifestyles and moving into duplexes and apartments.’
    1. 1.1A flat on two floors.
      [as modifier] ‘a plush Mayfair duplex flat’
      • ‘So we've had people here for quite a while living in huts, lean-tos, wood cabins and split-level duplexes with Italian marble counters.’
      • ‘A new scheme of 70 units, consisting of two- and three-bedroom apartments and duplexes, ranging in price from €245,000 to €280,000 and due to launch around January 20.’
      • ‘The terrace wrapped around the first floor of her duplex and was accessible from most rooms.’
      • ‘Under the plans the Wheatley would be converted to provide two, two bedroom duplexes and a pair of two bedroom flats.’
      • ‘The townhouses and three-bedroom duplexes will also include fireplaces, en suite bathrooms, downstairs guest bathrooms and tongue and groove timber flooring on the top floor.’
      • ‘Young families will be especially interested in the three-bedroom duplexes and townhouses.’
      • ‘Also available are three-bedroom duplexes on the ground and first floors; these have 105 square metres of accommodation and are selling for €228,000.’
      • ‘Duplex apartments start at €279,000 for a two-bedroom unit while a three-bed duplexes with gardens costs from €360,000.’
      • ‘The three-bed duplexes are located on the bottom two floors of the blocks with the two-bedroom apartments above.’
      • ‘Duplex apartments start at €310,000 for a two-bedroom unit, while three-bedroom duplexes with gardens are available from €385,000.’
      • ‘Three-bedroom duplexes with 1,195 sq ft of living space start at €385,000 and two-bedroom townhouses of 820 sq ft are priced from €360,000.’
      • ‘Studio flats at this converted mill have already been snapped up - guide prices started at £70,000 - but two- and three-bedroom duplexes are still available.’
      • ‘Two-bedroom townhouses and three-bedroom duplexes will be launched, with prices starting from €225,000.’
      • ‘Over the past few months he has shed more than 30 pounds and moved his family into a Park Avenue duplex, jetting back regularly to Vivendi's Paris headquarters on the company plane.’
      • ‘I understand that four and five bed duplexes are also available.’
      • ‘Above the one-bed apartments are the two-bedroom duplexes, priced from £168,950 and extending to 72 square metres.’
      • ‘Other features include en suite bathrooms in the two and three-bedroom units, private gardens with ground floor units and large balconies off the two-bed duplexes.’
      • ‘This elite section is where you find the big penthouses and duplexes.’
      • ‘The facades suggest that the apartment floor and unit arrangements may be double-height spaces, duplexes, or regular floors carefully hidden behind the cool glass facade.’
      • ‘Larger two-bedroom apartments and duplexes measuring 67 to 105 square metres cost between €265,000 and €429,500.’
    2. 1.2Australian A semi-detached house.
      • ‘In its place now sits four modern beige coloured duplexes.’
      • ‘Cahaba residents rented from the government until 1947, when the houses and duplexes were sold to individuals at prices ranging from $4,400 to $9,000 each.’
      • ‘We have been driving on the Hill of the Roses, where he stopped in front of a huge duplex.’
      • ‘It can be a house, duplex or apartment, but not a caravan or mobile home.’
      • ‘Snowdon residents have been duelling it out by petition concerning Addington House, a drug rehab centre recently transplanted from NDG to a semi-detached duplex at Earnscliffe and Dupuis.’
      • ‘When complete, KilgobbinWood will include a number of apartment blocks as well as five-bedroom detached, semi-detached houses, townhouses and duplexes.’
      • ‘You see, tensions run even higher because we actually live in a duplex.’
      • ‘The resolution, first reported on Feb.14, would place serious restrictions on the ability of students to live in houses and duplexes.’
      • ‘This category is restricted to people living in units, duplexes or Green-street style dwellings where lot sizes are 400 square metres or less.’
      • ‘A few hours later a helicopter thumps past the huskies curled up on top of their dog houses, past the newly built duplexes still wrapped in Tyvek.’
      • ‘The name means ‘style’ in Urdu, and the restaurant occupies the same duplex that used to house Girafe.’
      • ‘A total of 13 different unit styles will be available, including duplexes, townhouses and houses.’
      • ‘A major overseas developer has proposed an array of architecturally designed houses, duplexes and apartments up to eight storeys high on the Rifle Range block at the start of Papamoa Beach Rd.’
      • ‘She asked him to stop the car in front of a graceful duplex: a low, country house with wide porches complete with wooden table and chairs.’
      • ‘When completed the scheme will consist of 30 two-bedroom townhouses, eight three-bedroom end houses, 17 three-bedroom duplexes and 17 two-bedroom own door apartments.’
      • ‘The shelter uses half of a Yukon Housing duplex at Dugas Street and Front Street.’
      • ‘The architectural setting of casual schoolboys, in their smart suburban Ballajura school, can be contrasted with urban atmosphere of the Lincoln Street duplexes.’
      • ‘The resolution also includes a clause reiterating an existing law that prevents more than four unrelated persons from living together in one house or duplex.’
      • ‘More than 70 freestanding two-story houses in six configurations-from two-bedroom duplexes of 1,000 square feet to four-bedroom dwellings of 1,800 square feet-have been built so far.’
      • ‘Show apartments are open today from 2-5pm while the agents are also taking bookings for three-bed duplexes and five-bed houses elsewhere in the Addison Park scheme.’
  • 2Biochemistry
    A double-stranded polynucleotide molecule.

    • ‘Unlike larger polypeptides and proteins, small nucleic acid duplexes and hairpins do not have a dense core to which this effect would apply.’
    • ‘The drugs in the latter complexes are covalently connected by a peptide linker, whereas those associated with the oligonucleotide duplexes are chemically independent species.’
    • ‘In this work, the molar concentrations of the oligonucleotide duplexes are related to the double-stranded molecules 15-bp long.’
    • ‘Closed circular DNA usually exists in a supercoiled, plectonemic configuration, in which the DNA duplex is wound around another part of the same molecule to form a higher order helix.’
    • ‘Helicases are protein motors that use the energy of NTP hydrolysis to dissociate the hydrogen bonding between the nucleic acid duplexes and also to disrupt other non-covalent interactions between complementary base pairs.’


  • 1Having two parts, in particular.

    1. 1.1North American (of a house) consisting of two flats.
      • ‘One is for good quality standard apartments, duplex units or townhouses in central city locations or beside major employment or commercial centres.’
      • ‘There are also a few two-bedroom duplex townhouses available with prices starting at £160,000.’
      • ‘Prices for the three bedroom duplex houses, which measure 108 square metres, start at €400,000.’
      • ‘According to government statistics, the number of large units due for completion in 2005 will decline 60 per cent, not to mention duplex and luxury houses, supplies of which are expected to be scarce.’
      • ‘Each of the two-bedroom duplex townhouses in this phase will range in size from 82 to 98 square metres, with prices from €224,900.’
      • ‘Three-bedroom duplex houses start at £174,950 and have around 124 square metres of accommodation.’
      • ‘Exemptions on the thousands of apartments, single-family, and duplex homes built in that short five-year period amounted to almost a billion dollars.’
      • ‘Three bedroom duplex townhouses have around 120 square metres and start at £171,500.’
      • ‘Another part of the development is 24 two bedroom duplex houses, each having its own front garden.’
      • ‘The residential sector is 10,000 square feet in size and will include single family, duplex and multi-household residences constructed out of alternative building materials.’
      • ‘The development comprises a mix of three bedroom townhouses, four bedroom semi-detached and detached houses along with two bedroom apartments and three bedroom duplex houses.’
      • ‘The permission provided for the construction of 20 two-bedroom townhouses, eight two-bedroom duplex houses and eight one-bedroom garden level apartments.’
      • ‘In the three-bedroom duplex houses, the ground floor accommodation comprises a living room, separate kitchen/dining area and cloakroom.’
      • ‘The duplex houses are better where the bedrooms are on the first floor.’
      • ‘First-time buyers will be interested in the launch of phase two of Bryanstown Manor, a development of apartments and duplex houses near the train station in Drogheda, Co Louth.’
      • ‘The first batch of 40 two-bedroom apartments and three-bedroom duplex houses were completed and sold last February.’
    2. 1.2North American (of a flat) on two floors.
      • ‘They will be a mixture of one bedroom, two bedroom and duplex apartments.’
      • ‘Offers of around €700,000 will be considered for 5 Woodview, a duplex apartment located within a short walk of Blackrock village.’
      • ‘In addition, it is proposed to construct a duplex apartment containing a one-bedroom home on the ground floor and a two bedroom home spread over the first and second floors.’
      • ‘Two duplex apartments are stacked above a shop at ground level, the floors linked by a narrow communal staircase inserted into an intermediate slot between the new and old buildings.’
      • ‘Blocks A, B, C and D each incorporate 3 two bed townhouses, 4 two bed ground level apartments and 4 three bed duplex apartments.’
      • ‘There is full planning permission for a scheme of 12 two-bedroom duplex apartments and 18 car parking space.’
      • ‘The spacious three-bedroom duplex apartments contain between 102 and 139 square metres of living space and are priced from €257,000.’
      • ‘Well, it wasn't quite the top - there's a second floor to the duplex penthouse we couldn't make it to - but the views are magnificent, largely because the building is taller by half than most everything else in the neighborhood.’
      • ‘The plans provide for eight dwelling-houses, six ground floor apartments, six duplex apartments, an office and all ancillary site works.’
      • ‘Their scheme includes 12 two-bedroom duplex apartments in a two storey plus dormer block on part of the site, and the construction of a pub, lounge, community meeting room and ancillary services in a separate building on the site.’
      • ‘The company has applied to build 12 two-bedroom duplex apartments in a two-storey plus dormer block, as well as a public house in a two-storey plus dormer building with over basement car parking.’
      • ‘A total of 42 units are now available, at prices from €243,000 for a two-bedroom duplex apartment with a private roof garden and 70 square metres of accommodation.’
      • ‘There is a lot of cupboard space in both apartments and duplex apartments.’
      • ‘After a second or two, he pushes himself off the bed and heads down the hall to the stairwell of his duplex apartment.’
      • ‘This two bedroom duplex apartment has a private entrance hall and retains original Victorian features including high ceilings, decorative architraves and period fireplaces.’
      • ‘It will also incorporate a high tech business and conference centre, 66 duplex apartments, a leisure centre, entertainment centre, office development and crèche.’
      • ‘The top accommodation are duplex apartments costing 2,000 dollars a day per person.’
      • ‘The spacious four-bedroom duplex apartments are 116 square metres in size, with prices starting from €320,000.’
      • ‘It will comprise a retail unit, five ground floor flats and eight duplex apartments facing Holborn Street and three ground floor retail units, 17 apartments and 19 car parking spaces facing Markievicz Road.’
      • ‘This impressive duplex apartment lies in an exclusive development that enjoys a prime coastal position and well-tended communal gardens.’
    3. 1.3(of paper or board) having two differently coloured layers or sides.
      • ‘For a duplex sheet, two video images are received.’
      • ‘Finding an optimal schedule for general sheet sequences (e.g., with mixed simplex and duplex sheets in the same document) is still exponential.’
      • ‘However, newer machines can deliver documents either face-up or face-down, and thus simplex sheets are sometimes inverted, while duplex sheets sometimes are not inverted after the second image transfer.’
      • ‘For instance, a mark engine module controller may export exactly two functions, namely printing a simplex or duplex sheet.’
    4. 1.4(of a printer or its software) capable of printing on both sides of the paper.
      • ‘There are a number of innovative features, such as single-pass duplex scanning, which can cut your print runs in half.’
      • ‘Then we started arguing about how the printer managed to do duplex printing.’
      • ‘All of the printers in the new system can handle duplex printing.’
      • ‘Do you need a printer with duplex printing capability (the ability to print on both sides of the paper automatically)?’
      • ‘In order to simultaneously output and input a waveform, the sound card (or sound chip integrated on to the motherboard) must be capable of full duplex operation.’
  • 2(of a communications system, computer circuit, etc.) allowing the transmission of two signals simultaneously in opposite directions.

    • ‘This is because, unlike the regular duplex voice service, it need only be pseudo-realtime.’
    • ‘It, on the other hand, can support full duplex communications.’
    • ‘Twenty-one switches are interconnected in a tree topology, with Fast Ethernet trunking, providing 200 Mbps full duplex communication paths.’
    • ‘SAS supports dual-port and full duplex communication between servers and disk drives.’
    • ‘An adaptive electronic transmission signal cancellation circuit for separating transmit data from receive data in a bidirectional communication system operating in full duplex mode is disclosed.’
    • ‘An adaptive electronic transmission signal cancellation circuit separates transmit data from receive data in a bidirectional communication system operating in full duplex mode.’
    • ‘If proper operation ensues, the port remains configured for full duplex transmission.’
    • ‘These cables are either duplex, triplex, or quadruplex, consisting of one, two or three insulated conductors wrapped around a bare aluminum or ACSR neutral.’
    • ‘The cable TV system is not upgraded to support duplex data transfer right now.’
    • ‘When the error condition is detected, the port commences full duplex operation in a third operational state, based on the presumption that device at the other end of the link may be configured for fixed full duplex operation.’
    • ‘These products are high-performance, fully integrated duplex data links for bi-directional comms in fibre channel and other datacom applications.’
    • ‘The duplex audio would allow officers to hear each other at the far ends of the county and the dispatcher, even if they were talking, to hear an officer who began to transmit in contention.’
    • ‘While it offers interesting features like full duplex capability which allows callers to interrupt one another over IP - what is most impressive about the product is its clarity and lack of delay.’
    • ‘And those attributes are really ones of performance, in terms of the increased link speed, the dual-ported capability of the interface, and the full duplex nature of the interface.’
    • ‘This combination of features enables the user to hear and be heard in even the noisiest environments, while its full duplex communication technology ensures a natural flowing conversation.’
    • ‘To achieve high-quality IP telephony communications, a gateway must send a full duplex stream of small data packets in real time to satisfy the time division multiplexed telephony interface.’
    • ‘While disk drives have some full duplex capability, they typically can only be transferring user data in a single direction at a time.’
    • ‘The duplex circuit, developed in Germany, made it possible for messages to travel simultaneously in opposite directions on the same line.’


Mid 16th century (as an adjective): from Latin duplex, duplic-, from duo two + plicare to fold. The noun dates from the 1920s.