Definition of nasty :
1. Characterized by obcenity; indecent; indelicate; gross; filthy.
2. Hence, loosely: Offensive; disagreeable; unpropitious; wet; drizzling; as, a nasty rain, day, sky.
3. Offensively filthy; very dirty, foul, or defiled; disgusting; nauseous.
atrocious, critical, snappy, unsportsmanlike, immodest, fetid, tight, sozzled, scurrilous, loaded, hard, dangerous, dreaded, decent, miserly, poisonous, blind drunk, crocked, vile, coarse, tremendous, foul-smelling, odious, skanky, snappish, repellant, shameful, smashed, rotten, fuddled, irascible, awesome, unsporting, repellent, black, loathly, terrible, revolting, querulous, disgustful, besotted, noisome, low, broad, attitude, Fescennine, awful, horrid, pain, abominable, stringent, soaked, foetid, repelling, cruddy, raunchy, awing, ill-scented, obscene, cantankerous, pixilated, marked-up, fearful, fierce, filthy, stiff, horrendous, despiteful, cockeyed, bitchy, despicable, ribald, taut, gross, blotto, barnyard, crabby, difficult, grouchy, loathsome, antipathetic, unspeakable, slopped, ugly, sarcastic, mingy, inclement, cruel, abhorrent, scatologic, dread, pie-eyed, cross, injurious, unwholesome, good, profane, bawdy, bad-tempered, vulgar, ruthless, pissed, rigorous, clean, direful, noxious, amazing, lousy, contemptible, grotty, dirty, cheating, lewd, smutty, nauseating, repugnant, immoral, compressed, waspish, peevish, infamous, unclean, frightening, horrific, scatological, squalid, smelly, sloshed, afoul, sickening, awe-inspiring, cranky, despisable, wet, dire, crabbed, squiffy, fearsome, soused, soiled, petulant, painful, plastered, nefarious, like, detestable, ill-tempered, grumpy, wretched, yucky, fouled, funky, frightful, harmful, dreadful, shabby, surly, testy, stinking, malign, close, irritable, awed, fretful
disagreeable (part of speech: adjective)
malevolent (part of speech: adjective)
black-hearted, ill-natured, hurtful, malicious, hateful, sullen, evil, malignant, malevolent, rancorous, venomous, corrosive, virulent, spiteful, antagonistic, perfidious, catty, wicked, sinister, churlish, bitter, baleful, treacherous, vicious, mean, vindictive, foul, baneful, hostile
- It's been a hard case for all of us- a nasty one, explained the sheriff, as he placed a chair in front of the fire for her. - "The Hollow of Her Hand", George Barr McCutcheon.
- That would be a nasty one.... - "Miss Mapp", Edward Frederic Benson.
- D'you s'pose I'd touch the nasty stuff? - "The Panchronicon", Harold Steele Mackaye.