Nasty superl. : Offensively filthy; very dirty, foul, or defiled; disgusting; nauseous.

Nasty superl. : Hence, loosely: Offensive; disagreeable; unpropitious; wet; drizzling; as, a nasty rain, day, sky.

Nasty superl. : Characterized by obcenity; indecent; indelicate; gross; filthy.

Example:
What is the Nasty smelling stuff that dogs release when they are startled?

Taxonomy
Dictionary, Synonyms, offensive, adjective, weather, word origin, ty, ties, spiteful, nast, nasty accident, morally, Origin, ness, foul, repellent, villain, astre.

Defination from the web:
Nasty - Definition of Nasty at Dictionary.com a free online dictionary with pronunciation, synonyms, and translation of Nasty. Word of the Day and Crossword Puzzles. ... nasty. a combining form with the meaning "nastic pressure," of the kind or in the direction specified by the ...