in (adv., prep.)

a Middle English merger of Old English in (prep.) "in, into, upon, on, at, among; about, during;" and Old English inne (adv.) "within, inside," from Proto-Germanic *in (source also of Old Frisian, Dutch, German, Gothic in, Old Norse i), from PIE root *en "in." The simpler form took on both senses in Middle English.

Sense distinction between in and on is from later Middle English, and nuances in use of in and at still distinguish British and American English (in school/at school). Sometimes in Middle English shortened to i.

The noun sense of "influence, access (to power or authorities)," as in have an in with, is first recorded 1929 in American English. to be in for it "certain to meet with something unpleasant" is from 1690s. To be in with "on friendly terms with" is from 1670s. Ins and outs "intricacies, complications of an action or course" is from 1660s. In-and-out (n.) "copulation" is attested from 1610s.

in (adj.)

"that is within, internal," 1590s, from in (adv.). Sense of "holding power" (the in party) first recorded c. 1600; that of "exclusive" (the in-crowd, an in-joke) is from 1907 (in-group); that of "stylish, fashionable" (the in thing) is from 1960.

updated on October 10, 2018

Definitions of in from WordNet
in (adj.)
directed or bound inward;
took the in bus
the in basket
in (adj.)
holding office;
the in party
in (adj.)
currently fashionable;
large shoulder pads are in
in (n.)
a unit of length equal to one twelfth of a foot;
Synonyms: inch
in (n.)
a state in midwestern United States;
Synonyms: Indiana / Hoosier State / Ind.
in (adv.)
to or toward the inside of;
come in
smash in the door
Synonyms: inwards / inward
In (n.)
a rare soft silvery metallic element; occurs in small quantities in sphalerite;
Synonyms: indium / atomic number "
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