A person that is poor low class and is just one step above a hood. Known in the 50s-60s for greasy hair and dikis jean with converse has made them a fashion statement instead of a life style. Movies with greasers from the 60s are : "Cry baby" and "The Outsiders".
Ritchy person : Hey grease need a hair cut?
Ritchy: Too bad, Were gonna do you a favour and cut of all that long greasey hair