by
- 1Used to say who did, made, or caused something, as in 'a song by the Beatles.'
This song was written by my older sister when she was sixteen.
An attack by hackers shut the site down.
UsageOften after a verb like was written: was written by my sister. Also a song by, a visit by.
Note
- 2
- 3Used to give the amount of a change or a difference, as in 'up by ten'.
The price of gas went up by twenty cents this week.
She lost the race by less than one second.
UsagePut the amount after by: won by two points, up by ten.
Note
- 4Not later than a certain time, as in 'be home by ten'.
Please send in your homework by Friday at noon.
The new library should be finished by the end of the year.
UsageBy ten means at ten or earlier. Until ten means all the time up to ten.
Similarbefore
Note
- 5According to what someone says, or to a rule, law or way of measuring.
By law, every child in the car must wear a seat belt.
By the look of the sky, it's going to snow tonight.
UsageCommon in by law, by all accounts, and judge by.
Note
- 6Used to say what rule or feature is used to sort or arrange things.
I sorted the files by date.
The results are broken down by age and sex.
UsageUsually no article: sort by date, by name.
Less common meanings
- 7
- 8Used between measurements to give the size of something, as in 'ten by twenty'.
The room was about four foot by six foot.
The bricks measured ten by twenty by thirty centimeters.
UsageSay six by four; before a noun, a 6-by-4 photo.
- 9Past, along a route that goes close to someone or something.
We sat on the porch and watched the people walking by.
A car drove by very slowly.
UsageUsed after verbs like go and walk: time goes by.
Similarpast
Note
- 10Past something, moving close to it, as in 'he ran by me'.
A truck drove by the house and honked.
He ran straight by me without a word.
Similarpast
- 11
- 12Used in phrases like 'step by step' to show one after another, steadily.
The kids came into the room one by one.
Little by little, my English is getting better.
UsageSay step by step, one by one, with no article.
- 13In math, 'multiplied by', or in South Asian English 'divided by'.
Multiply the number of cartons by twelve to count the eggs.
Divide twelve by three.
UsageUsually it means times. To be clear, say times or over.
Similartimes
Note
- 14For each unit of time or amount, as in 'paid by the hour.'
Phone calls were charged by the minute, so she kept them short.
The pickers are paid by the bushel.
UsageSay by the hour or by the kilo, with the.
Similarper
Note
- 15
- 16Used to name the part of a person or thing that someone holds or grabs, or uses to lead them.
Mom took my little sister by the hand to cross the street.
Pick up the pot by the handle, not the side.
UsageSay by the arm or by the hand, with the.
- 17Used in oaths and exclamations to swear by something, as in 'by Jove!'.
By heaven, I will find out who broke my window!
By God, I never thought I'd see you again!
UsageUsed in swear by and in old cries like By heaven!
Note
- 18During a certain part of the day, mostly in by day and by night, often to show how the two times differ.
Owls sleep by day and hunt by night.
The old fort looks friendly by day but spooky by night.
UsageSay by day and by night, with no article.
- 19
- 20Extra or less important, or away from the main way, as in by-product or byway.
The by-catch was thrown back into the sea.
Sawdust is a by-product of cutting wood.
- 21In horse breeding, names the father of a horse, as in 'by Big Lad'.
- 22In sailing, toward the wind, as in 'by the wind' or 'full and by'.
- 23In Yeshivish English, 'at the home of', 'with', or 'among'.
Showing meanings only.
More uses
- by oneselfalone, or without anyone's help
Practice
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Origin
It comes from Old English "bī," meaning "by" or "near."
Checked 30 Oct 2026 · 1 fact
- The word by comes from Old English bī, meaning by or near. en.wiktionary.org