troll (v.)youdaoicibaDictYouDict
late 14c., "to go about, stroll," later (early 15c.) "roll from side to side, trundle," probably from Old French troller, a hunting term, "wander, to go in quest of game without purpose" (Modern French trôler), from a Germanic source (compare Old High German trollen "to walk with short steps"), from Proto-Germanic *truzlanan.

Sense of "sing in a full, rolling voice" (first attested 1570s) and that of "fish with a moving line" (c. 1600) both are extended technical uses from the general sense of "roll, trundle," the former from "sing in the manner of a catch or round," the latter perhaps confused with trail or trawl. Figurative sense of "to lure on as with a moving bait, entice, allure" is from 1560s. Meaning "to cruise in search of sexual encounters" is recorded from 1967, originally in homosexual slang.