Meaning

noun a bad-tempered person

noun a whimsically eccentric person

noun an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant

originFrom Middle English crank, cronk, from a shortening of Old English crancstæf (“weaving tool, crank”, literally “bent or crooked staff”), the first element ultimately related to Etymology 1 above.

Etymology from Wiktionary, CC BY-SA 3.0