a fusion of Old English hon "suspend" (transitive, class VII strong verb; past tense heng, past participle hangen), and Old English hangian "be suspended" (intransitive, weak, past tense hangode); also probably influenced by Old Norse hengja "suspend," and hanga "be suspended." All from Proto-Germanic *hanhan (transitive), *hanganan (intransitive) "to hang" (source also of Old Frisian hangia, Dutch hangen, German hängen), from PIE *konk- "to hang" (source also of Gothic hahan, Hittite gang- "to hang," Sanskrit sankate "wavers," Latin cunctari "to delay;" see also second element in Stonehenge).
As a method of execution, in late Old English (but originally specifically of crucifixion). Meaning "to come to a standstill" (especially in hung jury) is from 1848, American English. Hung emerged as past participle 16c. in northern England dialect, and hanged endured only in legal language (which tends to be conservative) in reference to capital punishment and in metaphors extended from it (I'll be hanged).
Teen slang sense of "spend time" first recorded 1951; hang around "idle, loiter" is from 1828, American English; also compare hang out. To hang back "be reluctant to proceed" is from 1580s; phrase hang an arse "hesitate, hold back" is from 1590s. Verbal phrase hang fire (1781) originally was used of guns that were slow in communicating the fire through the vent to the charge. To let it all hang out "be relaxed and uninhibited" is from 1967.
Old English cyssan "to touch with the lips" (in respect, reverence, etc.), from Proto-Germanic *kussjan (source also of Old Saxon kussian, Old Norse kyssa, Old Frisian kessa, Middle Dutch cussen, Dutch, Old High German kussen, German küssen, Norwegian and Danish kysse, Swedish kyssa), from *kuss-, probably ultimately imitative of the sound. Gothic used kukjan. Of two persons, "to reciprocally kiss, to kiss each other," c. 1300. Related: Kissed; kissing. The vowel was uncertain through Middle English; for vowel evolution, see bury.
Kissing, as an expression of affection or love, is unknown among many races, and in the history of mankind seems to be a late substitute for the more primitive rubbing of noses, sniffing, and licking. The partial agreement among some words for 'kiss' in some of the IE languages rests only on some common expressive syllables, and is no conclusive evidence that kissing was known in IE times. [Carl Darling Buck, "A Dictionary of Selected Synonyms in the Principal Indo-European Languages," 1949]
A common ku- sound may be found in the Germanic root and Greek kynein "to kiss," Hittite kuwash-anzi "they kiss," Sanskrit cumbati "he kisses." Some languages make a distinction between the kiss of affection and that of erotic love (compare Latin saviari "erotic kiss," vs. osculum, literally "little mouth"). French embrasser "kiss," but literally "embrace," came about in 17c. when the older word baiser (from Latin basiare) acquired an obscene connotation.
To kiss the cup "drink liquor" is early 15c. To kiss the dust "die" is from 1835. To kiss and tell is from 1690s. Figurative (and often ironic) kiss (something) goodbye is from 1935. To kiss (someone) off "dismiss, get rid of" is from 1935, originally of the opposite sex. Insulting invitation kiss my arse (or ass) as an expression of contemptuous rejection is from at least 1705, but probably much older (see "The Miller's Tale").