Words related to post-

before vowels ap-, word-forming element meaning "of, from, away from; separate, apart from, free from," from Greek apo "from, away from; after; in descent from," in compounds, "asunder, off; finishing, completing; back again," of time, "after," of origin, "sprung from, descended from; because of," from PIE root *apo- "off, away" (source also of Sanskrit apa "away from," Avestan apa "away from," Latin ab "away from, from," Gothic af, Old English of "away from," Modern English of, off).
a posteriori 
17c., in reference to reasoning from a consequent to its antecedent, from an effect to its cause; Latin, literally "from what comes after;" from a "off, away from," usual form of ab before consonants (see ab-) + posteriori, neuter ablative of posterius, comparative of posterus "after, subsequent," from post "after" (see post-). Opposed to a priori. In modern use (from c. 1830, based on Kant) roughly equivalent to "from experience."
ex post facto 
from Medieval Latin ex postfacto, "from what is done afterwards." From facto, ablative of factum "deed, act" (see fact). Also see ex-, post-.
pogrom (n.)

"organized massacre in Russia against a particular class or people, especially the Jews," 1882, from Yiddish pogrom, from Russian pogromu "devastation, destruction," from po- "by, through, behind, after" (cognate with Latin post-; see post-) + gromu "thunder, roar," from PIE imitative root *ghrem- (see grim).

post factum 

Latin, literally "after the fact," from post "behind, after, afterward" + factum "deed, act" (see post- + fact).

post meridiem 

"after noon, occurring after the sun has passed the meridian," applied to the time between noon and midnight, 1640s, Latin, from post "after" (see post-) + accusative of meridies "midday, noon" (see meridian).

post-bellum (adj.)

also postbellum, used in U.S. South from 1874 in reference to American Civil War; Latin; from post "after" (see post-) + bellum "war" (see bellicose).

post-Christian (adj.)

by 1807 as "after the lifetime of Christ," from post- + Christ + -ian; by 1929 as "after the decline or rejection of Christianity," from Christian.

post-classical (adj.)

"occurring or written after the times of the Greek or Latin writers considered classical, but before the literature classified as medieval," 1845, from post- + classical.

postdate (v.)

also post-date, "to affix a later date to than the real one," 1620s, from post- + date (v.1) "to assign a date to, to mark a date on." Related: Postdated; postdating. Intransitive meaning "be of a later date than" is by 1909.