retro-rocket n.

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.

garden plant of the cabbage family, c. 1500, rokette, from French roquette (16c.), perhaps via Italian rochetta, diminutive of ruca "a kind of cabbage," from Latin eruca "colewort," perhaps so called for its downy stems and related to ericus "hedgehog," also "a beam set with spikes" (from PIE *ghers- "to bristle;" see horror).