1.offensive or even (of persons) malicious;
in a nasty mood
2.exasperatingly difficult to handle or circumvent;
a nasty problem
3.thoroughly unpleasant;
filthy (or foul or nasty or vile) weather we're having
4.characterized by obscenity;
had a filthy mouth
5.disgustingly dirty; filled or smeared with offensive matter;
as filthy as a pigsty