retro-

1.
a prefix occurring in loanwords from Latin meaning “backward” (retrogress); on this model, used in the formation of compound words (retrorocket).
Origin
< Latin, representing retrō (adv.), backward, back, behind
British Dictionary definitions for retro-

retro-

prefix
1.
back or backwards: retroactive
2.
located behind: retrolental
Word Origin
from Latin retrō behind, backwards
Word Origin and History for retro-

word-forming element meaning "backwards; behind," from Latin retro (prep.) "backward, back, behind," also of time, "formerly, in past times," probably originally the ablative form of *reteros, based on re- "back" (see re-).

L. retro stands to re- as intro, "in, within"; to in, "in," and as citro, "hither," stands to cis, "on this side." [Klein]
Common in combinations in post-classical Latin (the classical equivalent was post-). Active in English as a word-forming element from mid-20c.

retro- in Medicine

retro- pref.

  1. Backward; back: retroposition.

  2. Situated behind: retroperitoneum.