mid-13c., "to cry out; call for, summon, invoke; ask for, demand, order; give a name to, apply by way of designation," from Old Norse kalla "to cry loudly, summon in a loud voice; name, call by name," from Proto-Germanic *kall- (source also of Middle Dutch kallen "to speak, say, tell," Dutch kallen "to talk, chatter," Old High German kallon "to speak loudly, call"), from PIE root *gal- "to call, shout." Related: Called; calling.
Old English cognate ceallian "to shout, utter in a loud voice" was rare, the usual word being clipian (source of Middle English clepe, yclept). Old English also had hropan hruofan, cognate of German rufen. Coin-toss sense is from 1801; card-playing sense "demand that the hands be shown" is from 1670s; poker sense "match or raise a bet" is by 1889. Meaning "to make a short stop or visit" (Middle English) was literally "to stand at the door and call." Telephone sense is from 1882.
To call for "demand, require" is from 1530s (earlier in this sense was call after, c. 1400). To call (something) back "revoke" is from 1550s. To call (something) off "cancel" is by 1888; earlier call off meant "summon away, divert" (1630s). To call (someone) names is from 1590s. To call out someone to fight (1823) corresponds to French provoquer. To call it a night "go to bed" is from 1919.
early 14c., "a loud cry, an outcry," also "a summons, an invitation," from call (v.). From 1580s as "a summons" (by bugle, drum, etc.) to military men to perform some duty; from 1680s as "the cry or note of a bird." Sense of "a short formal visit" is from 1862; meaning "a communication by telephone" is from 1878. From 1670s as "requirement, duty, right," hence, colloquially, "occasion, cause."
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.
1894, "anyone of a relationship not natural," abstracted from father-in-law, etc.
The position of the 'in-laws' (a happy phrase which is attributed ... to her Majesty, than whom no one can be better acquainted with the article) is often not very apt to promote happiness. [Blackwood's Magazine, 1894]
The earliest recorded use of the formation is in brother-in-law (13c.); the law is Canon Law, which defines degrees of relationship within which marriage is prohibited. Thus the word originally had a more narrow application; its general extension to more distant relatives of one's spouse is, according to OED "recent colloquial or journalistic phraseology." Middle English inlaue (13c.) meant "one within or restored to the protection and benefit of the law" (opposite of an outlaw), from a verb inlauen, from Old English inlagian "reverse sentence of outlawry."