Word Origin & History
O.E. spearca, from P.Gmc. *spark- (cf. M.L.G. sparke, M.Du. spranke, not found in other Gmc. languages). Electrical sense dates from 1748. Slang sense of "a gallant, a beau, a lover" (c.1600) is perhaps a fig. use, but also perhaps from cognate O.N. sparkr "lively." The verb is attested from c.1300;
the slang meaning "stimulate, to trigger" first attested 1912. Spark plug first recorded 1903 (sparking plug is from 1902); fig. sense of "one who initiates or is a driving force in some activity" is from 1941.