Nas″ty (nȧs″ty̆), a. [Compar.Nastier (–tĭ‐ẽr); superl.Nastiest.] [For older nasky; cf. dial. Sw. naskug, nasket.] 1. Offensively filthy; very dirty, foul, or defiled; disgusting; nauseous.
2. Hence, loosely: Offensive; disagreeable; unpropitious; wet; drizzling; as, a nasty rain, day, sky.
3. Characterized by obscenity; indecent; indelicate; gross; filthy.
Syn. — Nasty, Filthy, Foul, Dirty. Anything nasty is usually wet or damp as well as filthy or dirty, and disgusts by its stickiness or odor; but filthy and foul imply that a thing is filled or covered with offensive matter, while dirty describes it as defiled or sullied with dirt of any kind; as, filthy clothing, foul vapors, etc.