Definition of prep
Definition: Preppy -- contrary to belief -- is not so much an attitude (many confuse preppy with valley girl), but a style. Huge in the late '70s and early '80s with the cult classic "The Official Preppy Handbook," preppy clothing has never really gone out of style. The key is to mix prep-school staples (think plaid, polo tees, and pink & green) with fresh pieces for an unstuffy, downtown look.
Pronunciation: prep
Pronunciation: prep
Source...