by

BY/baɪ/

23 meanings of by

Practice

1
makerpreposition
Used to show who or what does, makes, or causes something, especially after a passive verb or a noun of action (built by the Romans; a novel by Tolstoy; a visit by the mayor).
The old bridge was built by the Romans nearly two thousand years ago.
A goal by the youngest player won the match.
UsageWith a short, simple doer after an action noun, a possessive also works: the mayor's visit instead of a visit by the mayor.
Note
An action noun can keep the doer of its verb: a call by the unions is the unions called, recast as a noun phrase. It is the by of a passive verb, as in the window was broken by the boy, carried over from verbs to nouns.
2
methodpreposition
Indicating the means of achieving something; using or involving.
You can reach the island only by boat.
He earned their trust by keeping his word.
Similarvia, through
3
amount of changepreposition
Indicating the amount of change, difference, or error.
She beat the record by two seconds.
The cash drawer was short by fifty dollars at closing.
UsageThe amount follows: win by two seconds, rise by ten percent. After rise and fall, by is often left out.
Note
The size of a gap is what follows. Up by ten percent gives the size of the rise, and wrong by ten years gives the size of the mistake. Sports results extend it to a full score, as in won by six goals to three.
4
no later thanpreposition
Not later than the stated time or the end of the stated period.
Applications must arrive by the fifteenth.
By the time we got there, the shop had shut.
UsageBy ten means at ten or before; until ten means the whole time up to ten. Learners often mix them up.
Similarbefore
Note
A deadline, not a duration, is the heart of it. With a period of time, it means before that period runs out: by the end of March, by the first week of July. Fixed forms like by now and by then work the same way.
5
preposition
According to a source, rule, law or standard, or under its authority (by law; by all accounts; by my watch).
By any measure the project was a success.
It's ten past, by the station clock.
UsageCommon in set phrases: by all accounts, by any measure, by law; and after judging verbs: judge people by their actions.
Note
Here the phrase names whose word or which yardstick you are trusting: by my reckoning, by his own admission, by all accounts. Wollaston in 1722 has people measuring others' actions by the tattle of their nurses. Keep it apart from the "means" meaning: by my watch says which clock you trust, not how the time was reached.
Checked 3 Nov 2026 · 2 facts
William Wollaston's The Religion of Nature Delineated was first published in 1722. en.wikipedia.org
Wollaston describes people measuring others' actions by the tattle of their nurses. en.wiktionary.org
6
preposition
Indicating the basis of a classification or arrangement.
Books are shelved by author, not by title.
The table shows spending by department.
UsageThe sorting word usually has no article: by author, by region. Tables often say broken down by or ranked by.

Less common meanings

7
besidepreposition
Near or next to; beside.
We had a picnic by the river.
Leave the keys by the door.
Similarbeside, near, alongside
Note
Nearness is what the word has meant from the start. In use it marks closeness rather than a fixed spot.
Checked 1 Nov 2026 · 1 fact
The meaning of nearness was already present in Old English. en.wiktionary.org
8
preposition
Separating the dimensions of something, such as length, width, and height.
The photo is six inches by four.
They cleared a strip thirty feet by two hundred.
UsagePut by between the figures: six inches by four. Before a noun, use hyphens: a 2-by-2 grid.
9
going pastadverb
Along a path that runs past someone or something; past.
We waved as the boat went by.
Time goes by so quickly in summer.
UsageCommon after motion verbs: go by, walk by, rush by; and for time: time goes by.
Similarpast
Note
Drop the object from the preposition of passing and this adverb is what remains: the parade passed by, with what it passed left unsaid. It stretches easily to time, as in the years slipped by.
10
going pastpreposition
Passing near something and continuing beyond it; past.
We drove by the old school on the way.
A stranger walked by the gate twice that morning.
Similarpast
11
visitadverb
To or at a place such as a home or business, usually for a brief visit.
A neighbor stopped by to borrow a ladder.
Can you come by this afternoon and pick up the signed forms?
UsageMostly in stop by, come by, drop by and swing by.
Similarround, over, in
12
bit at a timepreposition
Between two instances of a noun, or before a plural noun, marking a steady progression one unit after another.
The water rose inch by inch.
He paid off the debt little by little.
UsageRepeat the word with no article: inch by inch, step by step, one by one.
13
arithmeticpreposition
In mathematics, multiplied by, or, chiefly in South Asia, divided by.
Multiply the length by the width to get the area.
In her school they read the fraction as one by four.
UsageUsually read as times: three by four is twelve. If readers might take it as division, times or over is clearer.
Similartimes
Note
Two readings meet in arithmetic and can collide. In most English, a number by a number means multiplication. Chiefly in South Asia it can mean division, so one by four is a quarter rather than four. Multiplication is also what lies behind the dimension formula, since area is length times width.
Checked 3 Nov 2026 · 2 facts
Under the division reading, one by four equals one quarter. en.wiktionary.org
Multiplying length by width gives the area of a rectangle, explaining the connection with dimension expressions. openstax.org
14
for eachpreposition
In units of, or per (paid by the hour; sold by the dozen; by the thousands).
The boat is hired by the hour.
At the market, the eggs were sold by the dozen and the cheese by the pound.
UsageUsually with the: paid by the hour, sold by the dozen. Per is the formal equivalent for rates.
Similarper
Note
Rate and pace both fit here. Paid by the fortnight sets the unit of payment, and deteriorating by the day sets the unit of change. Both kinds can share one sentence, as in workers paid by the week and charged by the mile, one a period and one a quantity.
15
adverb
In the vicinity, near or at hand, as in 'close by' and 'hard by'.
Stay close by in case I need you.
A nurse sat by all night.
UsageUsually propped up: close by, hard by, or the single word nearby. Bare by survives in sit by and stand by.
Similarnear, nearby, around
Note
On its own the adverb now has a literary ring. Conrad's helmsman swaggers only while you were by.
Checked 3 Nov 2026 · 1 fact
Conrad’s helmsman is described as swaggering while someone is nearby and becoming frightened when that person is out of sight, in Heart of Darkness. gutenberg.org
16
part heldpreposition
Indicating the part of a person or thing that is gripped, as when seizing someone by the collar or leading a horse by the bridle.
The guard seized him by the collar and pulled him back from the edge.
She led the mare by the bridle across the muddy yard.
UsageUsually the, not a possessive: take someone by the arm, grab him by the collar.
17
oathpreposition
Invoking an authority or sacred thing in an oath or exclamation.
By heaven, you'll pay for this!
I swear by everything I hold dear that I never touched it.
UsageOften in swear by something, and in old exclamations such as By heaven! and By Jove!
Note
Swearing by something calls it as witness to your word, and the formula is old. Shakespeare writes By yonder moon I swear you do me wrong, and a Le Fanu character in 1863 exclaims By my soul! Many such oaths wore down into mere exclamations, as in By Jove! I think she's got it!, where nothing is actually sworn. The verb swear by keeps the full sense.
Checked 30 Oct 2026 · 5 facts
The oath formula is old: Shakespeare wrote 'By yonder moon I swear you do me wrong'. Gratiano speaks the line to Nerissa in The Merchant of Venice, Act 5, scene 1. folger.edu
A Le Fanu character exclaims 'By my soul!': Sturk says it in The House by the Church-yard, chapter XLIII. celt.ucc.ie
1863 is the first book-publication year of The House by the Church-yard, as printed on its title page. catalogue.nli.ie
Oath formulas developed into exclamations; 'by Jove' was originally a literal oath and later became a minced oath. en.wiktionary.org
'By Jove! I think she's got it!' is attested with exactly this wording as an unattributed dictionary example. en.wiktionary.org
18
preposition
Within a given part of the day, mostly in the paired phrases by day and by night, used to contrast what happens at those times.
He worked as a bank teller by day and played jazz clubs by night.
Seen by night, the city's skyline glitters like a jewelry case.
UsageNo article: by day, by night. With the, by the day means per day instead.
19
asideadverb
Aside or away, saved for later, now mostly in the phrase 'put by'.
Every week she put by a few coins.
We had wood put by for the cold months.
UsageNearly always put by, with the object on either side: put money by, put by some money. Put aside is the neutral choice.
Similaraside, away
20
side matteradjective
Secondary, incidental, or off to one side, mainly in compounds (by-product, by-election, byway).
For her, new friendships were a welcome by-product of joining the choir.
Sea turtles caught in shrimp nets are a common by-catch.
21
preposition
In horse breeding, used to name a horse's sire, with 'out of' naming the dam.
22
preposition
In sailing, in a windward direction, close to the direction the wind comes from.
23
preposition
In Yeshivish English, at, at the house of, with, or among.

More uses

by oneselfalone, or without anyone's help

Practice

Can you tell the meanings of by apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.

Origin

It comes from Middle English "by" or "bi," from Old English "bī" meaning "by, near, or around," going back through Proto-Germanic "*bi," possibly to Proto-Indo-European "*h₁epi." It is related to Dutch "bij" and German "bei."

Checked 30 Oct 2026 · 2 facts

English by comes through Middle English by or bi and Old English bī, meaning by, near, or around, from Proto-Germanic *bi. en.wiktionary.org
English by is related to Dutch bij and German bei. en.wiktionary.org