come (v.)youdaoicibaDictYouDict[come 词源字典]
Old English cuman "come, approach, land; come to oneself, recover; arrive; assemble" (class IV strong verb; past tense cuom, com, past participle cumen), from Proto-Germanic *kwem- (cognates: Old Saxon cuman, Old Frisian kuma, Middle Dutch comen, Dutch komen, Old High German queman, German kommen, Old Norse koma, Gothic qiman), from PIE root *gwa-, *gwem- "to go, come" (cognates: Sanskrit gamati "he goes," Avestan jamaiti "goes," Tocharian kakmu "come," Lithuanian gemu "to be born," Greek bainein "to go, walk, step," Latin venire "to come").

The substitution of Middle English -o- for Old English -u- before -m-, -n-, or -r- was a scribal habit before minims to avoid misreading the letters in the old style handwriting, which jammed letters. The practice similarly transformed some, monk, tongue, worm. Modern past tense form came is Middle English, probably from Old Norse kvam, replacing Old English cuom.

Remarkably productive with prepositions (NTC's "Dictionary of Phrasal Verbs" lists 198 combinations); consider the varied senses in come to "regain consciousness," come over "possess" (as an emotion), come at "attack," come on (interj.) "be serious," and come off "occur." For sexual senses, see cum.[come etymology, come origin, 英语词源]
granny (n.)youdaoicibaDictYouDict
also grannie, 1660s, according to OED, most likely a diminutive and contraction of grannam, shortened form of grandame, rather than from grandmother. The sailor's granny knot (by 1803), originally granny's knot, readily jammed and insecure, is a reef or square knot with the second part crossed the wrong way, so called in contempt because "it is the natural knot tied by women or landsmen" [Smyth, "Sailor's Word-Book," 1867]. Granny Smith apples (1895) are said to have been named for Maria Ann Smith (d. 1870) of Australia, who originated them. Granny glasses attested from 1966.
jam (v.)youdaoicibaDictYouDict
"to press tightly," also "to become wedged," 1706, of unknown origin, perhaps a variant of champ (v.). Of a malfunction in the moving parts of machinery, by 1851. Sense of "cause interference in radio signals" is from 1914. Related: Jammed; jamming. The adverb is recorded from 1825, from the verb.
monkey (n.)youdaoicibaDictYouDict
1520s, likely from an unrecorded Middle Low German *moneke or Middle Dutch *monnekijn, a colloquial word for "monkey," originally a diminutive of some Romanic word, compare French monne (16c.); Middle Italian monnicchio, from Old Italian monna; Spanish mona "ape, monkey." In a 1498 Low German version of the popular medieval beast story Roman de Renart ("Reynard the Fox"), Moneke is the name given to the son of Martin the Ape; transmission of the word to English might have been via itinerant entertainers from the German states.

The Old French form of the name is Monequin (recorded as Monnekin in a 14c. version from Hainault), which could be a diminutive of some personal name, or it could be from the general Romanic word, which may be ultimately from Arabic maimun "monkey," literally "auspicious," a euphemistic usage because the sight of apes was held by the Arabs to be unlucky [Klein]. The word would have been influenced in Italian by folk etymology from monna "woman," a contraction of ma donna "my lady."

Monkey has been used affectionately for "child" since c. 1600. As a type of modern popular dance, it is attested from 1964. Monkey business attested from 1883. Monkey suit "fancy uniform" is from 1886. Monkey wrench is attested from 1858; its figurative sense of "something that obstructs operations" is from the notion of one getting jammed in the gears of machinery (compare spanner in the works). To make a monkey of someone is attested from 1900. To have a monkey on one's back "be addicted" is 1930s narcotics slang, though the same phrase in the 1860s meant "to be angry." There is a story in the Sinbad cycle about a tormenting ape-like creature that mounts a man's shoulders and won't get off, which may be the root of the term. In 1890s British slang, to have a monkey up the chimney meant "to have a mortgage on one's house." The three wise monkeys ("see no evil," etc.) are attested from 1926.