prep (n.)youdaoicibaDictYouDict[prep 词源字典]
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 etymology, prep origin, 英语词源]
prep (v.)youdaoicibaDictYouDict
slang shortening of prepare, 1908. Related: Prepped; prepping.