post-graduate adj.

word-forming element meaning "after," from Latin post "behind, after, afterward," from *pos-ti (source also of Arcadian pos, Doric poti "toward, to, near, close by;" Old Church Slavonic po "behind, after," pozdu "late;" Lithuanian pas "at, by"), from PIE *apo- (source also of Greek apo "from," Latin ab "away from" see apo-).

early 15c., "one who holds a degree" (originally with man; as a stand-alone noun from mid-15c.), from Medieval Latin graduatus, past participle of graduari "to take a degree," from Latin gradus "a step; a step climbed (on a ladder or stair);" figuratively "a step toward something, a degree of something rising by stages" (from PIE root *ghredh- "to walk, go"). As an adjective, from late 15c.