American Dictionary

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Definition by in American English

by adverb, preposition

adverb, preposition
/baɪ/

By can be used in the following ways:

as a preposition (followed by a noun): The building was destroyed by fire.

as an adverb (without a following noun): As time went by, things improved.

1

used, especially with passive verbs, for showing who does something or what causes something

1.1

used, especially with passive verbs, for showing who does something or what causes something

Example

Injured refugees were treated by a Red Cross doctor.

Example

Hull House was founded by Jane Addams in 1889.

Example

Children are fascinated by the idea of magic.

Example

The fabric had been faded by the sun.

1.2

used for saying who wrote a book or a piece of music, who painted a picture, etc.

Example

a novel by Graham Greene

Example

mural paintings by Diego Rivera

2

using a particular method to achieve something

2.1

using a particular method to achieve something

Example

Reading is taught by traditional methods here.

Example

The palace balcony is shielded by bulletproof glass.

Example

Every bit of lace is made by hand (=not using a machine).

Example

By using the Internet you can do your shopping from home.

Example

They exchanged New Year's greetings by e-mail.

Example

We'll send you the tickets by mail.

Example

Sophie's parents arrived by taxi.

Synonyms and related words
2.3

using a particular road, path, door, etc.

Example

We returned home by a different route.

Example

She went in by the side entrance.

2.4

using a particular name or title

Example

Staff members generally address each other by their first name.

Example

The U.N. refugee agency is known by its initials UNHCR.

Synonyms and related words
2.5

used for saying how you start or finish something

Example

I'm going to start off by explaining the purpose of our campaign.

3

not later than a particular time or date

3.1

not later than a particular time or date

Example

The meeting should have finished by 4:30.

Example

Application forms must be received by March 31st.

Synonyms and related words
3.2

during the period until a particular time or date

Example

By mid afternoon over 5,000 people had visited the exhibition.

Example

By the time Charlotte was 15, she had already achieved worldwide fame.

Synonyms and related words
4

used when saying that something happens in a way that was not planned or intended

Example

Take care that you don't shoot one of us by mistake.

Example

We met quite by chance.

Example

By a stroke of luck I found the perfect title for my new book.

5

used for saying that time passes, or how it passes

Example

As time went by, people's attitudes changed.

Example

The days seem to fly by.

Example

I find that Friday afternoons just drag by (=go very slowly).

Synonyms and related words
6

used for showing how much something has changed, or how much difference there is between things

Example

House prices rose by an average 23% last year.

Example

Owen broke the world record by 2.4 seconds.

7

used for saying that someone or something goes past you

Example

She walked right by me without saying a word.

Example

There were angry shouts from the crowd as the president's motorcade drove by.

8

beside or close to someone or something

Example

She was sitting over there by the window.

Example

There's an ashtray just by your elbow.

Synonyms and related words
9

according to rules or laws

Example

In the police force we have to do everything by the rulebook.

Synonyms and related words
10

used for showing that something is judged according to certain standards of behavior, quality, etc.

Example

It's no use trying to judge 18th-century morality by modern standards.

Example

Her performance was amazing by any standard.

Synonyms and related words
11

used for saying that someone stops somewhere for a short time, especially while going to another place

Example

Why don't you stop by on your way home from work?

Example

Peggy dropped by the office this afternoon.

Synonyms and related words
12

used for saying which part of a person's body or thing you take in your hand when you hold them

Example

Taking me by the arm, she led me into the next room.

Example

Always pick up a CD by the outer edge to avoid damaging the surface.

13

used for referring to someone's personality, job, origin, name, etc.

Example

She was, by nature, a cheerful and friendly sort of person.

Example

An American by birth, Cassidy had spent much of his life in Bolivia.

14

used for saying what units of measurement are used

14.1

used for saying what units of measurement are used

Example

Floor coverings are priced by the square foot.

Example

Industrial workers are generally paid by the hour.

Example

sold by the dozen

14.2

used for giving the size of an area, object, or space by stating its length, width, height, etc.

Example

The house has a spacious dining room, measuring 18 by 15 feet.

Example

I usually get 4 by 6 inch prints of my pictures.

Synonyms and related words
15

used when saying that something happens or changes gradually

15.1

used when saying that something happens or changes gradually

Example

Little by little Philip got used to life on the farm.

Example

His medical condition is continuing to improve day by day.

15.2

used when things or people do something or are dealt with one after the other

Example

One by one the men came forward to receive their medals.

Example

The finance committee checks through each document, item by item.

Definition by in American English

Related Words

Words related to by:

abide by (phrasal verb) (all) by herself (phrase) (all) by himself (phrase) (all) by itself (phrase) (all) by myself (phrase) (all) by oneself (phrase) as if by magic (phrase) bit by bit (phrase) blow-by-blow (adjective) brush-by (noun) by (adverb, preposition) by a mile (phrase) by a neck (phrase) by a whisker (phrase) by accident (phrase) by air (phrase) by all means (phrase) by and by (phrase) by and large (phrase) by any chance (phrase) by association (phrase) by choice (phrase) by default (phrase) by definition (phrase) by degrees (phrase) by design (phrase) by example (phrase) by extension (phrase) by far (phrase) by foot (phrase) by George (interjection) by God (phrase) by golly (phrase) by gum (phrase) by hand (phrase) by heart (phrase) by mistake (phrase) by name (phrase) by (phrase) by no means (phrase) by prescription (phrase) by profession (phrase) by reason of (phrase) by rights (phrase) by the book (phrase) by the bucket (phrase) by the by (phrase) by the hour (phrase) by the minute (phrase) by the numbers (phrase) by the time (phrase) by the way (phrase) by turns (phrase) by-election (noun) contrast (phrase) call by (phrasal verb) cheek by jowl (phrase) come by (phrasal verb) creep by (phrasal verb) day by day (phrase) die by (phrasal verb) drag by (phrasal verb) drive-by (adjective) drive-by (noun) drop by (phrasal verb) fly-by (noun) fly-by-night (adjective) fly-by-wire (noun) four-by-four (noun) get by (phrasal verb) go by (phrasal verb) inch by inch (phrase) lay-by (noun) learn by doing (phrase) little by little (phrase) live by (phrasal verb) month by month (phrase) one by one (phrase) pass by (phrasal verb) passer-by (noun) play it by ear (phrase) play-by-play (noun) put by (phrasal verb) run by (phrasal verb) scrape by (phrasal verb) sell-by date (noun) side by side (phrase) sit by (phrasal verb) slip by (phrasal verb) stand by (phrasal verb) step by step (phrase) step-by-step (adjective) stick by (phrasal verb) stop by (phrasal verb) swear by (phrasal verb) swing by (phrasal verb) trial by fire (phrase) trial by jury (phrase) use-by date (noun) year by year (phrase)