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Definition of by
(Entry 1 of 5)
1 : in proximity to : near standing by the window
2a : into the vicinity of and beyond : past went right by him
b : through or through the medium (see medium entry 1 sense 2) of : via enter by the door
c : in the direction of : toward sailed north by east
3a : during the course of studied by night
b : not later than be there by 2 p.m.
4a : through the agency (see agency sense 3) or instrumentality of a poem written by Keats death by firing squad taken by force happened by luck
b : born or begot of had two sons by his first wife one child by her second husband
c : sired or borne by having foals by champion race horses
5 : with the witness or sanction (see sanction entry 1 sense 4c) of swear by all that is holy
6a : in conformity with acted by the rules
b : according to called her by name sold by the pound
7 —used as a function word in multiplication, in division, and in measurementsdivide a by bmultiply 10 by 4a room 15 feet by 20 feet
8a : with respect to a lawyer by profession
b : on behalf of did right by his children
9 : in or to the amount or extent of win by a nose
10 —used as a function word to indicate successive units or incrementslittle by littlewalk two by two
11 : in the opinion of : from the point of view of OK by me
by
adverbDefinition of by (Entry 2 of 5)
by
nounvariants: or bye
Definition of by (Entry 3 of 5)
: something of secondary importance : a side issue by the by
by
adjectivevariants: or bye
Definition of by (Entry 4 of 5)
1 : being off the main route : side a by passage
2 : incidental by effects
by
interjectionvariants: or bye
Definition of by (Entry 5 of 5)
—used to express farewell —often used with following now
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A More Exception(al) Quiz
- Which of the following words is not a synonym for ‘a young person’?
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Can you spell these 10 commonly misspelled words?
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Merriam-Webster unabridgedWords at Play
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Time Traveler for by
The first known use of by was before the 12th century
See more words from the same century