preparatory adj.

mid-15c., "set in order or readiness for a particular end," a back formation from preparation and in part from Old French preparer (14c.), from Latin praeparare "to make ready beforehand," from prae "before" (see pre-) + parare "to make ready" (from PIE root *pere- (1) "to produce, procure"). Compare pare (v.), which is from the same Latin verb. Related: Prepared; preparer; preparing.

Intransitive sense of "make (oneself) ready beforehand" is from c. 1500. The sense of "bring into a particular mental state with reference to the future" is by 1520s. The sense of "make (food) ready to eat" is from late 15c. (Caxton). The meaning "provide or procure for future use" is from 1530s. An earlier verb was preparate (late 14c.), from Latin praeparatus, past participle of praeparare. The Boy Scouts' motto Be Prepared is attested from 1911, based, as he said, on the initials of the organization's founder, Robert Baden-Powell.

"serving or tending to prepare the way or make ready for something to follow," c. 1400, preparatif, from Old French preparatif and directly from Medieval Latin preparativus, from stem of Latin praeparare (see prepare).

1862, short for preparation. Prep school is attested from 1895, short for preparatory school. First record of prep in the college slang sense "student or graduate of a preparatory school, student taking a preparatory course of study" is by 1899 (also see preppie).