Meaning

adjective offensive or even (of persons) malicious; ; ; ; ; ; - Ezra Pound

adjective exasperatingly difficult to handle or circumvent

adjective characterized by obscenity

originFrom Middle English nasty, nasti, naxty, naxte (“unclean, filthy”), whence also Early Modern English nasky (“nasty”), of obscure origin. Probably from earlier Middle English *naskty, *naskedy, from Middle English *nasked (“dirty, messy”) + -y, ultimately of North Germanic origin (comparable to Danish nasket (“dirty, foul, unpleasant”), Swedish naskot (“dirty, filthy”), Swedish naskig, naskug…

Etymology from Wiktionary, CC BY-SA 3.0