The definition of nasty is something that is very dirty, unpleasant or offensive.(adjective)
See nasty in Webster's New World College Dictionary
Origin: ME < ? or akin to Du nestig, dirty
noun pl. nasties
See nasty in American Heritage Dictionary 4
adjective nas·ti·er, nas·ti·est
Origin: Middle English nasti
Origin: , possibly alteration of Old French nastre, bad
Origin: , short for villenastre
Origin: : vilein, bad; see villain
Origin: + -astre, pejorative suff. (from Latin -aster).
Origin: Greek nastos, pressed down; see nastic
Origin: + -y2.
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