英语词源字典 - 在线词源网站

roister (v.)[roister 词源字典]: "bluster, swagger, be bold, noisy, vaunting, or turbulent," 1580s, from an obsolete noun roister "noisy bully" (1550s, displaced by 19c. by roisterer), from Middle French ruistre "ruffian," from Old French ruiste "boorish, gross, uncouth," from Latin rusticus (see rustic (adj.)). Related: Roistered; roistering. Ralph Royster-Doyster is the title and lead character of what is sometimes called the first English comedy (Udall, 1555).[roister etymology, roister origin, 英语词源]
shaver (n.): "one who shaves," early 15c., agent noun from shave (v.); sense of "fellow, chap" is slang from 1590s. Meaning "shaving tool" is from 1550s. Mad shaver (1610s) was 17c. slang for "a swashbuckler, roisterer."
spark (n.): Old English spearca "glowing or fiery particle thrown off," from Proto-Germanic *spark- (cognates: Middle Low German sparke, Middle Dutch spranke, not found in other Germanic languages). Electrical sense dates from 1748. Old French esparque is from Germanic.

Slang sense of "a gallant, a showy beau, a roisterer" (c. 1600) is perhaps a figurative use, but also perhaps from cognate Old Norse sparkr "lively." Spark plug first recorded 1902 (sparking plug is from 1899); figurative sense of "one who initiates or is a driving force in some activity" is from 1941.