Definition of orbital in US English:



  • 1Relating to an orbit or orbits.

    • ‘Hubble and other orbital observatories may join in too.’
    • ‘Unlike the Soyuz, the orbital module was equipped with its own propulsion, solar power, and control systems, allowing autonomous flight.’
    • ‘With its emphasis on accurate space flight simulation and orbital mechanics, Orbiter is not all things to all space and astronomy enthusiasts.’
    • ‘This creates increased atmospheric drag on spacecraft in low orbits, shortening their orbital lifetime.’
    • ‘Many asteroids are members of groups with very similar orbital shapes, tilts, and solar distances.’
    • ‘It was quickly realized that a previously known anomaly in the orbital motion of Mercury was explicable with the relativistic theory.’
    • ‘This nearly polar orbit is designed such that the spacecraft's orbital path moves at the same apparent rate as the Sun.’
    • ‘Kepler's third law of planetary motion says that the square of the planet's orbital period is proportional to the cube of its semimajor axis.’
    • ‘If the orbital velocity is increased, the orbit moves outward from the Sun; if the velocity is decreased, the orbit moves inward toward the Sun.’
    • ‘Another problem with comets is that, unlike their asteroid cousins, their orbital parameters are often poorly known and therefore difficult to project into the future to see if they pose any threat.’
    • ‘Instead, Virgin is looking at the possibility of orbital spaceflight.’
    • ‘Currently, orbital spaceflight is available to those who are willing to pay the price.’
    • ‘After his orbital flight, Gagarin made many public appearances and in 1966 began training for a Soyuz flight.’
    • ‘If there is sufficient interest, I will then examine the effects of orbital flight and orbital operations.’
    • ‘Its slightly elongated orbit takes it around the star in about 13 years, comparable to Jupiter's orbital period of 11.86 years.’
    • ‘A list of all the phases of flight that a reusable orbital launcher must successfully transit is truly daunting.’
    • ‘Objects in orbit change orbital paths fairly often.’
    • ‘Suborbital and orbital transportation, however, do not require any property rights.’
    • ‘Planetary mass, size, and orbital dynamics are the properties that make up this second proposed definition.’
    • ‘In fact, all the planets orbit the sun close to such a fixed orbital plane.’
    1. 1.1British (of a road) passing around the outside of a town.
      • ‘Minister Parlon said the site in question was strategically located near the partially completed orbital road which makes it more attractive for locating the Department of Agriculture headquarters on, he added.’
      • ‘Motorists have been given diversions through Mill Hill or the orbital route and traffic jams are expected.’
      • ‘Plans for a new orbital road around Ballina are moving forward and a display of the proposals will be made for the general public early next month.’
      • ‘On February 1st they kick-started the tendering process for the extension of the M77 to Fenwick and the creation of the new Glasgow southern orbital road.’
      • ‘The contract will in effect involve the widening of all the remaining three-lane sections of the M25 to four lanes, and cover 100 km of the London orbital motorway.’
      • ‘The city is physically contained by the orbital M25 motorway with its 31 junctions.’
      • ‘Apple has confirmed its third UK retail location: the Bluewater shopping centre in Kent, just outside London's M25 orbital freeway.’
      • ‘London's orbital M25, between junctions five and 21, was the worst followed by the A303 from Andover, Hampshire, onwards.’
      • ‘It is set off the main road from London to Portsmouth, the naval town on the south coast, and nowadays the intersection of this road and the London orbital motorway lies in Ockham Wood.’
      • ‘The road turned out to be La Periphique, the orbital motorway that has been built more or less precisely on the boundary between the city of Paris and its suburbs.’
      • ‘Before the shake-up of Blackburn's roads to create the orbital route in 2001, Freckleton Street bridge carried traffic from King Street to Bolton Road.’
      • ‘A report by banking group Halifax revealed that the top 30 towns for price growth were all outside the M25 London orbital motorway, and Brighouse headed the list.’
      • ‘Plans were shelved at that time until the Blackburn orbital route was complete.’
      • ‘Until now, traffic travelling from the Preston Old Road side of town has been directed either through the town centre or round the orbital route.’
      • ‘Work should start in the summer, and will mean the end of a rat-run used by motorists trying to avoid traffic lights on the town centre orbital route.’
      • ‘A young, obese psychic spends her days driving the orbital road surrounding London, pulling up at struggling community halls or greasy steakhouses to perform stage shows.’
      • ‘The M60 ‘missing link’ between Middleton and Denton opened in October 2000 and was the final piece in Manchester's orbital motorway.’
      • ‘Despite Mum's apprehensions we made the motorway journey from Little Walden (north of Cambridge) down to the London orbital road and out to Portsmouth without a hiccup.’
      • ‘The concept of an orbital road around the capital had been discussed since the Royal Commission on London Traffic in 1905.’
      • ‘It is thought that a fully completed, two-way orbital route will also make the town centre more attractive.’
      • ‘Up to 400 horseboxes could be involved, potentially bringing the orbital motorway to a standstill.’


  • Each of the actual or potential patterns of electron density that may be formed in an atom or molecule by one or more electrons, and that can be represented as a wave function.

    • ‘It is also possible for two orbitals on each atom to overlap, forming two molecular orbitals between the two atoms.’
    • ‘In chemical reactions, it is the electrons in these orbitals that form or break bonds between different atoms.’
    • ‘The effect is due to the distortion of the electron orbitals because of the magnetic field.’
    • ‘The ground state of the molecule is that in which the bonding electrons are in the molecular orbitals of lowest energy.’
    • ‘In addition, it can also lead to daunting calculations as each atom contributes its orbitals to the whole molecule.’


Mid 16th century (referring to the eye socket): probably from medieval Latin orbitalis, from Latin orbita (see orbit).