Definition of by in English:



  • 1Identifying the agent performing an action.

    by means of, by use of, by virtue of, on account of, as a result of, as a consequence of, owing to, by reason of, on grounds of, on the strength of, due to, thanks to, by, via
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    1. 1.1 After a passive verb.
      ‘the door was opened by my cousin Annie’
      ‘damage caused by fire’
      through the agency of, by means of, under the aegis of, using, utilizing, employing, with the help of, with the aid of, as a result of, because of, by dint of, by way of, by virtue of, via, through
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    2. 1.2 After a noun denoting an action.
      ‘further attacks by the mob’
      ‘a clear decision by the electorate’
    3. 1.3 Identifying the author of a text, idea, or work of art.
      ‘a book by Ernest Hemingway’
  • 2[often with verbal noun] Indicating the means of achieving something.

    ‘malaria can be controlled by attacking the parasite’
    ‘they plan to provide further working capital by means of borrowing’
    1. 2.1 Indicating a term to which an interpretation is to be assigned.
      ‘what is meant by “fair?”’
    2. 2.2 Indicating a name according to which a person is known.
      ‘she mostly calls me by my last name’
    3. 2.3 Indicating the means of transport selected for a journey.
      ‘traveling by train to Boston’
    4. 2.4 Indicating the other parent of someone's child or children.
      ‘Richard is his son by his third wife’
    5. 2.5 Indicating the sire of a pedigree animal, especially a horse.
      ‘a black filly by Goldfuerst’
    6. 2.6 (followed by a noun without an adjective) in various phrases indicating how something happens.
      ‘I heard by chance that she has married again’
      ‘Anderson, by contrast, rejects this view’
      ‘she ate by candlelight’
  • 3Indicating the amount or size of a margin.

    ‘the shot missed her by miles’
    ‘the raising of taxes by 2.5%’
    1. 3.1 Indicating a unit of measurement.
      ‘billing is by the minute’
    2. 3.2 In phrases indicating something happening repeatedly or progressively, typically with repetition of a unit of time.
      ‘colors changing minute by minute’
      ‘the risk becomes worse by the day’
    3. 3.3 Identifying a parameter.
      ‘a breakdown of employment figures by age and occupation’
    4. 3.4 Expressing multiplication, often in dimensions.
      ‘a map measuring 24 by 36 inches’
      ‘she multiplied it by 89’
  • 4Indicating a deadline or the end of a particular time period.

    ‘I've got to do this report by Monday’
    ‘by now Kelly needed extensive physiotherapy’
    no later than, in good time for, at, before
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  • 5Indicating location of a physical object beside a place or object.

    ‘remains were discovered by the roadside’
    ‘the lamp was by the door’
    next to, beside, next door to, alongside, at the side of, by the side of, abreast of, adjacent to, cheek by jowl with, side by side with
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    1. 5.1 Past; beyond.
      ‘I drove by our house’
      past, in front of, beyond
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  • 6Indicating the period in which something happens.

    ‘this animal always hunts by night’
  • 7Concerning; according to.

    ‘anything you do is all right by me’
    ‘she had done her duty by him’
    according to, with, as far as ... is concerned, concerning
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  • 8Used in mild oaths.

    ‘it was the least he could do, by God’


  • So as to go past.

    ‘a car flashed by on the other side of the road’
    ‘he let only a moment go by’
    past, on, along, beyond
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  • variant spelling of bye


  • by and by

    • Before long; eventually.

      eventually, ultimately, finally, in the end, as time goes by, as time goes on, one day, some day, sooner or later, in time, in a while, after a bit, in the long run, in the fullness of time, at a later time, at a later date, at length, at a future date, at a future time, at some point in the future, in the future, in time to come, in due course
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  • by the by (or bye)

    • Incidentally; parenthetically.

      ‘where's Hector, by the by?’
      less important, of less importance, secondary, subsidiary, subordinate, ancillary, auxiliary
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  • by and large

    • On the whole; everything considered.

      ‘mammals have, by and large, bigger brains than reptiles’
      largely, mostly, mainly, to a large extent, to a great extent, to a great degree, on the whole, chiefly, generally, in general, predominantly, substantially, primarily, overall, for the most part, in the main, principally, in great measure, preponderantly, first and foremost, for all intents and purposes, basically
      usually, typically, commonly
      on the whole, generally, in general, altogether, all things considered, all in all, taking everything into consideration, for the most part, in the main, as a rule, overall, usually, normally, ordinarily, almost always, customarily, habitually, typically, mainly, mostly, basically, chiefly, predominantly, principally, substantially
      on average, in most cases, on balance, to all intents and purposes
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  • by oneself

    • 1Alone.

      ‘living in that big house by himself’
      alone, all alone, on one's own, in a solitary state, singly, separately, solitarily, unaccompanied, companionless, partnerless, unattended, unescorted, unchaperoned, solo
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    • 2Unaided.

      ‘the patient often learns to undress by himself’
      unaided, unassisted, without help, without assistance, by one's own efforts, under one's own steam, independently, solo, on one's own, alone, all alone, off one's own bat, on one's own initiative
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  • by way of

    • 1So as to pass through or across; via.

      ‘we approached the Berlin Wall by way of Checkpoint Charlie’
      • ‘Drive on to reach a viaduct, cross this and turn immediately right by way of a metal gate into Cairnsmore Estate.’
      • ‘They passed from cellar to cellar by way of holes in the walls.’
      • ‘He returned to the main post in the vestibule by way of three long connecting buildings on Wilkins Road.’
      • ‘The heart then pumps the oxygen-rich blood through the body by way of arteries.’
      • ‘He voted in Texas, then made his way back to Washington by way of Columbus, Ohio.’
      • ‘We made it there in the end, although admittedly by way of thirty-odd roundabouts, and sat at a long dim table in a corner where four of the lights had blown.’
      • ‘This was also the period in which Buddhism spread throughout China, arriving by way of India.’
      • ‘It resembles Arabian couscous, from which it probably originated, traveling to the Spanish colonies by way of the mother land.’
      • ‘He traveled no farther than four miles outside of Nevaharday by way of the trade route.’
      • ‘We by-pass a farm with fine barns and cross another idyllic little stream by way of four large stepping-stones.’
      • ‘It was August, sunny and hot, and we were on a trip from Iowa to Wyoming by way of the scenic wonders of South Dakota.’
    • 2Constituting; as a form of.

      ‘“I can't help it,” shouted Tom by way of apology’
      • ‘Although the reference is to a change resulting from a court or tribunal ruling, that is by way of example.’
      • ‘I asked whether it was a nice gesture of my host that he'd managed to collate the past decade's songs by way of a celebration.’
      • ‘She stood her ground. A year later, her boss bought her a £7,000 piano by way of apology.’
      • ‘What would be necessary by way of reparation, apology, atonement for that to be acceptable?’
      • ‘The team has had plenty of glory days in the past, but of late their efforts have brought little by way of reward.’
      • ‘He claimed he'd only sent some of the items by way of an apology.’
      • ‘Now, by way of thanks, he is being awarded the freedom of East Lothian.’
      • ‘Maybe I should post a few of them by way of illustration.’
      • ‘It may even be that the House may find it necessary to place some arbitrary limit on awards of damages that are made by way of punishment.’
      • ‘Almost three quarters of the way through his reign, he has accomplished virtually nothing by way of political reform.’
    • 3By means of.

      ‘noncompliance with the regulations is punishable by way of a fine’
      • ‘Several car manufacturers are expected to pass on the excise reliefs to the consumers by way of reduced prices.’
      • ‘Agree in advance by way of a contract what you wish them to do and what the charges will be on an hourly basis.’
      • ‘Fans had applied for passes to these gigs by way of a text message and lottery-draw system.’
      • ‘Well, the Constitution can be changed by the people by way of a referendum.’
      • ‘She gave birth to a healthy baby boy three years ago by way of in vitro fertilization.’
      • ‘A past district governor of Rotary illustrates this by way of his personal experience on the streets of Malawi.’
      • ‘The majority of cost increases come by way of contracted pay and benefit hikes.’
      • ‘Unfortunately, this has been passed on to farmers by way of lower prices paid to farmers.’
      • ‘Bryson makes his way through the British countryside, towns and cities by way of bus, train, or on foot.’
      • ‘They add to the local economy through knowledge transfer by way of training, research and development.’


Old English bī, bi, be, of Germanic origin; related to Dutch bij and German bei.