adjective, nas·ti·er, nas·ti·est.
- physically filthy; disgustingly unclean: a nasty pigsty of a room.
- offensive to taste or smell; nauseating.
- offensive; objectionable: a nasty habit.
- vicious, spiteful, or ugly: a nasty dog; a nasty rumor.
- bad or hard to deal with, encounter, undergo, etc.; dangerous; serious: a nasty cut; a nasty accident.
- very unpleasant or disagreeable: nasty weather.
- morally filthy; obscene; indecent: a nasty word.
- Slang. formidable: The young pitcher has a good fast ball and a nasty curve.
noun, plural nas·ties.
- Informal. a nasty person or thing.
adjective -tier or -tiest
- unpleasant, offensive, or repugnant
- (of an experience, condition, etc) unpleasant, dangerous, or painfula nasty wound
- spiteful, abusive, or ill-natured
- obscene or indecent
- nasty piece of work British informal a cruel or mean person
noun plural -ties
- an offensive or unpleasant person or thinga video nasty
adj.c.1400, “foul, filthy, dirty, unclean,” of unknown origin; perhaps [Barnhart] from Old French nastre “miserly, envious, malicious, spiteful,” shortened form of villenastre “infamous, bad,” from vilein “villain” + -astre, pejorative suffix, from Latin -aster. Alternative etymology [OED] is from Dutch nestig “dirty,” literally “like a bird’s nest.” Likely reinforced in either case by a Scandinavian source (cf. Swedish dialectal naskug “dirty, nasty”), which also might be the source of the Middle English word. Of weather, from 1630s; of things generally, “unpleasant, offensive,” from 1705. Of people, “ill-tempered,” from 1825. Noun meaning “something nasty” is from 1935. Related: Nastily; nastiness.