Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “by”

by

preposition     strong /baɪ/ weak /, /
DO A2 used to show the person or thing that does something: She was examined by a doctor. The building had been destroyed by fire. a painting by Van GoghCausing things to happen
HOW A2 through doing or using something: Can I pay by cheque? I sent it by email. We'll get there by car. [+ doing sth] Open the file by clicking on the icon.Causing things to happen
HOLDING B2 holding a particular part of someone or something: She grabbed me by the arm.Having in your hands
NEAR B1 near or next to something or someone: I'll meet you by the post office. A small child stood by her side.Next to and beside
NOT LATER A2 not later than a particular time or date: Applications have to be in by the 31st.Before, after and alreadyAfter and behind
ACCORDING TO according to: By law you must be eighteen to purchase alcohol.Being based on or depending on somethingQuoting and making references
PAST past: He sped by me on a motorcycle.General words for movement
AMOUNT used to show measurements or amounts: twelve by ten metres of floor space Interest rates have been increased by 0.25%. I'm paid by the hour. Copies have sold by the million.Weighing and measuring
by accident/chance/mistake, etc B1 as a result of an accident/chance/mistake, etc: I went to the wrong room by mistake.Not expected or planned
by day/night during the day/nightRelating to regular periods of time
day by day/little by little/one by one, etc used in particular phrases to mean 'gradually' or 'in units of': Day by day he grew stronger.Slow and moving slowly
(Definition of by preposition from the Cambridge Learner's Dictionary © Cambridge University Press)

Definitions of “by” in other dictionaries

Word of the Day

well in (with)

to have a good relationship with someone in which they like you and from which you get an advantage

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More