Meaning : Offensive or even (of persons) malicious.
Example :
In a nasty mood.
A nasty accident.
A nasty shock.
A nasty smell.
A nasty trick to pull.
Will he say nasty things at my funeral?.
Synonyms : awful
Pleasant or pleasing or agreeable in nature or appearance.
What a nice fellow you are and we all thought you so nasty.Meaning : Exasperatingly difficult to handle or circumvent.
Example :
A nasty problem.
A good man to have on your side in a tight situation.
Synonyms : tight