Someone who is incredibly greasy or oily and has not been in the shower for quite some time. Some say that a greaser can be dripping with grease. Quite frankly it is disgusting.
A type of person who greases their hair back in style of the 1950s greasers listens to RockaBilly kinds of music and are the heppest catsyou know
Guy1:hey you know that greaser?
Guy2:you mean Johnny.
Guy1:yeah I'm gonna beat his ass!
2 hours later Guy2:what happened too you?
Guy1:he beat my ass 6 ways til Sunday.
Johnny:dont never show yo face around here anymore ya dig?