badinage (n.)youdaoicibaDictYouDict[badinage 词源字典]
"light railery," 1650s, from French badinage "playfulness, jesting," from badiner (v.) "to jest, joke," from badin "silly, jesting," from Old Provençal badar "to yawn, gape," from Late Latin badare "to gape," from *bat-, the root of abash.[badinage etymology, badinage origin, 英语词源]
gaud (n.)youdaoicibaDictYouDict
early 15c., "a bauble, trinket," earlier "a large, ornamental bead in a rosary" (mid-14c.), probably mistakenly taken as singular of earlier gaudy (n.) "large, ornamental rosary bead" (early 14c., in plural form gaudeez), later "ornamentation" generally (late 14c.), which is from Medieval Latin gaudia and Old French gaudie "joy, pleasure, playfulness; a piece of showy finery, a flashy trinket," from Latin gaudium "joy," gaude "rejoice thou" (in hymns), from gaudere "rejoice" (see joy (n.), and compare jewel (n.)).

Also in Middle English "a jest, prank, trick" (late 14c.); "a deception, fraud, artifice" (mid-14c.). As a verb, "to furnish with gauds," from late 14c. Related: Gauded; gauding; gaudful; gaudless.
heyday (n.)youdaoicibaDictYouDict
late 16c., alteration of heyda (1520s), exclamation of playfulness or surprise, something like Modern English hurrah, apparently an extended form of Middle English interjection hey or hei (see hey). Modern sense of "stage of greatest vigor" first recorded 1751, which altered the spelling on model of day, with which this word apparently has no etymological connection.
lascivious (adj.)youdaoicibaDictYouDict
mid-15c., from Middle French lascivieux or directly from Late Latin lasciviosus (used in a scolding sense by Isidore and other early Church writers), from Latin lascivia "lewdness, playfulness, frolicsomeness, jolity," from lascivus "lewd, playful, frolicsome, wanton," from PIE *las-ko-, from *las- "to be eager, wanton, or unruly" (cognates: Sanskrit -lasati "yearns," lasati "plays, frolics," Hittite ilaliya- "to desire, covet," Greek laste "harlot," Old Church Slavonic laska "flattery," Slovak laska "love," Old Irish lainn "greedy," Gothic lustus, Old English lust "lust"). Related: Lasciviously; lasciviousness. In 17c. also with a verbal form, lasciviate.
playful (adj.)youdaoicibaDictYouDict
mid-13c., from play (v.) + -ful. Related: Playfully; playfulness.