grandstand (n.)youdaoicibaDictYouDict[grandstand 词源字典]
"main seating for spectators at an outdoor event," 1761 (two words), from grand (adj.) + stand (n.). The verb meaning "to show off" is student slang from 1895, from grandstand player, attested in baseball slang from 1888.
It's little things of this sort which makes the 'grand stand player.' They make impossible catches, and when they get the ball they roll all over the field. [M.J. Kelly, "Play Ball," 1888]
Compare British gallery hit (1882) "showy play by a batsman in cricket, 'intended to gain applause from uncritical spectators'" [OED]. Related: grandstanding.[grandstand etymology, grandstand origin, 英语词源]
groovy (adj.)youdaoicibaDictYouDict
1850, "pertaining to a groove," from groove (n.) + -y (2). Slang sense of "first-rate, excellent" is 1937, American English, from jazz slang phrase in the groove (1932) "performing well (without grandstanding)." As teen slang for "wonderful," it dates from c. 1941; popularized 1960s, out of currency by 1980. Earlier colloquial figurative sense was "having a tendency to routine, inclined to a specialized and narrow way of life or thought" (1882). Related: Grooviness.