Etymology From Middle English by, bi, from Old English bī (“by; near; around”), from Proto-West Germanic *bī, from Proto-Germanic *bi (“near; by; around; about”), from Proto-Indo-European *h₁epi. Cognate with West Frisian by (“by; near”), Afrikaans by (“at; by; near”), Saterland Frisian bie (“near; by”), Dutch bij (“near; by”), German Low German bi (“by; near; at”), German bei (“by; near; at”).
From one side of something to the other, passing close by; past.
The stream runs by our back door.
He ran straight by me.
3
Not later than (the given time); not later than the end of (the given time interval); before.
Be back by ten o'clock!
We'll find someone by the end of March.
1 more example
I'll have been cycling for longer than two hours by lunchtime.
4
After a given amount of time has elapsed or a given event has occurred.
By February, we were all sick of the cold.
By the time I realized I had left my phone at home, I was already two blocks from work.
1 more example
By 29, my financial situation wasn’t just disorganized, it was untenable.2026 April 22, Jillian Sanders, “The Danger of Surrendering Your Financial Independence in a Relationship”, in TIME, archived from the original on 22 Apr 2026:
› Indicates the person or thing that does or…
5
Following a passive verb.
The matter was decided by the chairman.
The boat was swamped by the water.
2 more examples
He was protected by his body armour.
Valencia threatened sporadically in the first half with Miguel having a decent effort deflected wide by Ashley Cole, while Jordi Alba's near-post cross was flicked into the sidenetting by Pablo Hernandez.2011 September 28, Jon Smith, “Valencia 1-1 Chelsea”, in BBC Sport, archived from the original on 30 Jun 2022:
6
Following a noun.
There was a call by the unions for a 30% pay rise.
7
Not in common modern use Following an adjective.
I was aghast by what I saw.
In other directions the fields and sky were so much of one colour by the snow that it was difficult in a hasty glance to tell whereabouts the horizon occurred […].1874, Thomas Hardy, Far from the Madding Crowd, 2005 Barnes & Noble Classics publication of 1912 Wessex edition, p.109
1 more example
Nina is pregnant by a wishy-washy ACLU lawyer named Howard.1986 February 15, Walta Borawski, “Objects of Affection: Gay Men & Straight Women”, in Gay Community News, volume 14, number 39, page B6:
8
Indicates the creator of a work: Existing through the authorship etc. of.
There are many well-known plays by William Shakespeare
9
Indicates a means of achieving something: Involving/using the means of.
I'd know you anywhere by your gravelly voice.
I avoided the guards by moving only when they weren't looking.
4 more examples
By Pythagoras' theorem, we can calculate the length of the hypotenuse.
We went by bus.
I discovered it by chance.
By 'maybe' she means 'no'.
10
Indicates an authority according to which something is done.
By the power vested in me, I now pronounce you man and wife.
I live by my own code of ethics.
11
Invokes an authority in an oath.
By Jove! I think she's got it!
By all that is holy, I'll put an end to this.
2 more examples
By yonder moon I swear you do me wrongc. 1596–1598 (date written), William Shakespeare, “The Merchant of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act V, scene i]:
'By my soul! I believe something bad has happened me,' he muttered, and popped up his window, and looked out, half dreaming over the church-yard on the park beyond […]1863, Sheridan Le Fanu, The House by the Churchyard:
12
Indicates a means of classification or organisation.
I sorted the items by category.
Table 1 shows details of our employees broken down by sex and age.
13
Indicates the amount of change, difference or discrepancy
Our stock is up by ten percent.
We won by six goals to three.
1 more example
His date of birth was wrong by ten years.
14
In the formulae X by X and by Xs, indicates a steady progression, one X after another.
We went through the book page by page.
We crawled forward by inches.
15
[with the] Acted on in units of the specified size or measure. (Sometimes hyperbolically)
sold by the yard; cheaper if bought by the gross
While sitting listening to the radio by the hour, she can drink brandy by the bucketful!
1 more example
He sits listening to the radio by the hour.
16
Per; with or in proportion to each.
His health was deteriorating by the day.
The pickers are paid by the fortnight by the American bushel.
17
Indicates a referenced source: According to.
He cheated by his own admission.
By my reckoning, we should be nearly there.
1 more example
Ignorant and ſuperſtitious wretches meaſure the actions of letterd and philoſophical men by the tattle of their nurſes or illiterate parents and companions, or by the faſhion of the country : and people of differing religions judge and condemn each other by their own tenents ; when both of them cannot be in the right, and it is well if either of them are.1722, William Wollaston, “Sect. V. Truths relating to the Deity. Of his exiſtence, perfection, providence, &c.”, in The Religion of Nature Delineated, page 81:
18
Used to separate dimensions when describing the size of something.
It is easy to invert a 2-by-2 matrix.
The room was about 4 foot by 6 foot.
1 more example
The bricks used to build the wall measured 10 by 20 by 30 cm.
19
Mathematics, Sciences multiplied by or (chiefly South Asia) divided by
20
Designates a horse's sire (“male parent”).
She's a lovely little filly, by Big Lad, out of Damsel in Distress.
21
At; with; among.
Chiefly Yeshivish
Are you eating by Rabbi Fischer? (at the house of)
By Chabad, it's different.
22
Nautical, Transport in a windward direction, sailing near to the direction from which the wind is blowing
Etymology From Middle English by, bi, from Old English bī (“by; near; around”), from Proto-West Germanic *bī, from Proto-Germanic *bi (“near; by; around; about”), from Proto-Indo-European *h₁epi. Cognate with West Frisian by (“by; near”), Afrikaans by (“at; by; near”), Saterland Frisian bie (“near; by”), Dutch bij (“near; by”), German Low German bi (“by; near; at”), German bei (“by; near; at”).
1
Along a path which runs past someone or something.
I watched the parade as it passed by.
2
In the vicinity, near.
There was a shepherd close by.
[The helmsman] steered with no end of a swagger while you were by; but if he lost sight of you, he became instantly the prey of an abject funk […]1899 March, Joseph Conrad, “The Heart of Darkness”, in Blackwood’s Edinburgh Magazine, volume CLXV, number MI, New York, N.Y.: The Leonard Scott Publishing Company, […], →OCLC, part II:
3
To or at a place, as a residence or place of business.
I'll stop by on my way home from work.
We're right near the lifeguard station. Come by before you leave.
4
Aside, away.
Uncommon outside the phrase 'put by'
The women spent much time after harvest putting jams by for winter and spring.
Etymology From Middle English by, bi, from Old English bī (“by; near; around”), from Proto-West Germanic *bī, from Proto-Germanic *bi (“near; by; around; about”), from Proto-Indo-European *h₁epi. Cognate with West Frisian by (“by; near”), Afrikaans by (“at; by; near”), Saterland Frisian bie (“near; by”), Dutch bij (“near; by”), German Low German bi (“by; near; at”), German bei (“by; near; at”).
Etymology From Middle English by, bi, from Old English bī (“by; near; around”), from Proto-West Germanic *bī, from Proto-Germanic *bi (“near; by; around; about”), from Proto-Indo-European *h₁epi. Cognate with West Frisian by (“by; near”), Afrikaans by (“at; by; near”), Saterland Frisian bie (“near; by”), Dutch bij (“near; by”), German Low German bi (“by; near; at”), German bei (“by; near; at”).