retro-: back, backwards
spect: derived from Latin "specere", meaning "look"
-ive: [something]of doing something
So retrospective means:
[Something] Of looking back (to an earlier state).
- "Of looking back to an earlier state" is an adjective, meaing "of retrospecting".
- "Something of looking back to an earlier state" is a noun, meaning "retrospection".
Evolution of usage
Let's take something of looking back to the earlier states of the history of human evolution.
Let's take something of retrospecting of the history of human evolution.
Let's take a retrospective of the history of human evolution.