Also found in: Idioms.
prep·pyor prep·pie (prĕp′ē)Informal
n. pl. prep·pies
1. A student or former student of a preparatory school.
2. A person whose manner and dress are deemed typical of traditional preparatory schools.
adj. prep·pi·er, prep·pi·est
Of or relating to a preppy or a preparatory school.
informal the fact of being preppy