retrospective (adj.)

c. 1600, "a regard or reference" (to something), from Latin retrospectum, past participle of retrospicere "look back," from retro "back" (see retro-) + specere "look at" (from PIE root *spek- "to observe"). Meaning "survey of past events" is from 1660s.

word-forming element making adjectives from verbs, meaning "pertaining to, tending to; doing, serving to do," in some cases from Old French -if, but usually directly from Latin adjectival suffix -ivus (source also of Italian and Spanish -ivo). In some words borrowed from French at an early date it has been reduced to -y (as in hasty, tardy).