"copulation backward," of various quadrupeds the male of which faces in the opposite direction from the female during the act, 1640s, from retro- + copulation. Related: Retrocopulate (v.).
Entries linking to retrocopulation
retro-
word-forming element of Latin origin meaning "backwards; behind," from Latin retro (prep.) "backward, back, behind," usually in reference to place or position, rarely of time, "formerly, in the past," 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.
copulation n.
late 14c., copulacioun, "a coupling, joining, uniting," from Latin copulationem (nominative copulatio) "a coupling, joining, connecting," noun of action from past-participle stem of copulare "join together, couple, bind, link, unite," from copula "band, tie, link" (see copulate). Specific sense of "sexual intercourse, coition" is from late 15c., and this became the main sense from 16c.