# by

Pronunciation: US say "BY" /baɪ/; UK

## Preposition

1. 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).
   - Simple: Used to say who did, made, or caused something, as in 'a song by the Beatles.'
   - _The old bridge was built by the Romans nearly two thousand years ago._
   - _A goal by the youngest player won the match._
2. Indicating the means of achieving something; using or involving.
   - Simple: Used to say how something is done or what is used to do it, as in 'go by bus'.
   - _You can reach the island only by boat._
   - _He earned their trust by keeping his word._
3. Indicating the amount of change, difference, or error.
   - Simple: Used to give the amount of a change or a difference, as in 'up by ten'.
   - _She beat the record by two seconds._
   - _The cash drawer was short by fifty dollars at closing._
4. Not later than the stated time or the end of the stated period.
   - Simple: Not later than a certain time, as in 'be home by ten'.
   - _Applications must arrive by the fifteenth._
   - _By the time we got there, the shop had shut._
5. According to a source, rule, law or standard, or under its authority (by law; by all accounts; by my watch).
   - Simple: According to what someone says, or to a rule, law or way of measuring.
   - _By any measure the project was a success._
   - _It's ten past, by the station clock._
6. Indicating the basis of a classification or arrangement.
   - Simple: Used to say what rule or feature is used to sort or arrange things.
   - _Books are shelved by author, not by title._
   - _The table shows spending by department._
7. Near or next to; beside.
   - Simple: Near or next to a person or thing.
   - _We had a picnic by the river._
   - _Leave the keys by the door._
8. Separating the dimensions of something, such as length, width, and height.
   - Simple: Used between measurements to give the size of something, as in 'ten by twenty'.
   - _The photo is six inches by four._
   - _They cleared a strip thirty feet by two hundred._
10. Passing near something and continuing beyond it; past.
   - Simple: Past something, moving close to it, as in 'he ran by me'.
   - _We drove by the old school on the way._
   - _A stranger walked by the gate twice that morning._
12. Between two instances of a noun, or before a plural noun, marking a steady progression one unit after another.
   - Simple: Used in phrases like 'step by step' to show one after another, steadily.
   - _The water rose inch by inch._
   - _He paid off the debt little by little._
13. In mathematics, multiplied by, or, chiefly in South Asia, divided by.
   - Simple: In math, 'multiplied by', or in South Asian English 'divided by'.
   - _Multiply the length by the width to get the area._
   - _In her school they read the fraction as one by four._
14. In units of, or per (paid by the hour; sold by the dozen; by the thousands).
   - Simple: For each unit of time or amount, as in 'paid by the hour.'
   - _The boat is hired by the hour._
   - _At the market, the eggs were sold by the dozen and the cheese by the pound._
16. 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.
   - Simple: Used to name the part of a person or thing that someone holds or grabs, or uses to lead them.
   - _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._
17. Invoking an authority or sacred thing in an oath or exclamation.
   - Simple: Used in oaths and exclamations to swear by something, as in 'by Jove!'.
   - _By heaven, you'll pay for this!_
   - _I swear by everything I hold dear that I never touched it._
18. 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.
   - Simple: During a certain part of the day, mostly in by day and by night, often to show how the two times differ.
   - _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._

## Adverb

9. Along a path that runs past someone or something; past.
   - Simple: Past, along a route that goes close to someone or something.
   - _We waved as the boat went by._
   - _Time goes by so quickly in summer._
11. To or at a place such as a home or business, usually for a brief visit.
   - Simple: To someone's home or workplace, for a short visit, as in 'stop by'.
   - _A neighbor stopped by to borrow a ladder._
   - _Can you come by this afternoon and pick up the signed forms?_
15. In the vicinity, near or at hand, as in 'close by' and 'hard by'.
   - Simple: Near, close to the place being talked about, as in 'close by'.
   - _Stay close by in case I need you._
   - _A nurse sat by all night._
19. Aside or away, saved for later, now mostly in the phrase 'put by'.
   - Simple: Aside, to be kept for later, almost only in 'put by'.
   - _Every week she put by a few coins._
   - _We had wood put by for the cold months._

## Adjective

20. Secondary, incidental, or off to one side, mainly in compounds (by-product, by-election, byway).
   - Simple: Extra or less important, or away from the main way, as in by-product or 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._

## Other meanings

- (preposition) In horse breeding, used to name a horse's sire, with 'out of' naming the dam.
- (preposition) In sailing, in a windward direction, close to the direction the wind comes from.
- (preposition) In Yeshivish English, at, at the house of, with, or among.

## 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."

Source: DictionaryAI, https://dictionaryai.com/define/by (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).