"a revolving machine consisting of wooden horses or seats mounted on a circular platform," 1729, from merry (adj.) + go-round. Figurative use by 1838. Merry-totter (mid-15c.) was a Middle English name for a swing or see-saw. Also compare merry-go-down "strong ale" (c. 1500); merry-go-sorry "a mix of joy and sorrow" (1590s).
c. 1200, from Old English gamen "joy, fun; game, amusement," common Germanic (cognates: Old Frisian game "joy, glee," Old Norse gaman "game, sport; pleasure, amusement," Old Saxon gaman, Old High German gaman "sport, merriment," Danish gamen, Swedish gamman "merriment"), said to be identical with Gothic gaman "participation, communion," from Proto-Germanic *ga- collective prefix + *mann "person," giving a sense of "people together."
The -en was lost perhaps through being mistaken for a suffix. Meaning "contest for success or superiority played according to rules" is first attested c. 1200 (of athletic contests, chess, backgammon). Especially "the sport of hunting, fishing, hawking, or fowling" (c. 1300), thus "wild animals caught for sport" (c. 1300), which is the game in fair game (see under fair (adj.)), also gamey. Meaning "number of points required to win a game" is from 1830. Game plan is 1941, from U.S. football; game show first attested 1961.
c. 1300, "to strike with a quick, sharp motion, to slap," from Old English clæppan "to throb, beat," or from or influenced by its Old Norse cognate, klappa, a common Germanic echoic verb (compare Old Frisian klapa "to beat," Old High German klaphon, German klappen, Old Saxon klapunga).
Meaning "to make a sharp noise" is late 14c. Of hands, "to beat together to get attention or express joy," from late 14c. Without specific mention of hands, "to applaud, to manifest approbation by striking the hands together," 1610s. To clap (someone) on the back is from 1520s and retains the older sense. Related: Clapped; clapping.
1530s, in the Roman historical sense, from French ovation or directly from Latin ovationem (nominative ovatio) "a triumph, rejoicing," noun of action from past-participle stem of ovare "exult, rejoice, triumph," probably imitative of a shout (compare Greek euazein "to utter cries of joy").
In Roman history, a lesser triumph, granted to a commander for achievements (such as defeat of an inconsiderable enemy, accomplished with little bloodshed), insufficient to entitle him to a triumph proper. The figurative sense of "burst of enthusiastic applause from a crowd" is attested by 1831.
1877, "a Russian commune or village," also (with capital M-) the name of a late 20c. space station, Russian, literally "peace, world," also "village, community," from Old Church Slavonic miru "peace," from Proto-Slavic *miru "commune, joy, peace" ("possibly borrowed from Iranian" [Watkins]), from PIE root *mei- (4) "to bind, tie" (see mitre). Old Church Slavonic miru was "used in Christian terminology as a collective 'community of peace' " [Buck], translating Greek kosmos. Hence, "the known world, mankind."
early 13c., from Old English la, exclamation of surprise, grief, joy, or mere greeting; probably merged with or influenced in Middle English by lo!, which is perhaps short for lok "look!" imperative of loken "to look" (see look (v.)). Expression lo and behold attested by 1779. In old U.S. slang, Lo was a generic name for an Indian or the Indians collectively (1871), from jocular use of Pope's line "Lo, the poor Indian" ["Essay on Man"].