A hair style from the fifties characterized by copious use of pomade, and its height. The term greaser is usually associated with this hair style, and can be attributed to the pomade which is typically used to construct the pompadour.
Good examples of pompadours can be found on Ricky Ricardo from I Love Lucy, young Elvis Presley photos, Johnny Bravo (I know, cartoon character, but good pomp nonetheless), Chris Issac, Morrissey and any of the Stray Cats.