prep (n.)youdaoicibaDictYouDict
1862, short for preparation. Prep school attested from 1895, short for preparatory school. First record of prep in the sense "student or graduate of a preparatory school" is from 1899 (also see preppie).
prep (v.)youdaoicibaDictYouDict
slang shortening of prepare, 1908. Related: Prepped; prepping.