The Collaborative International Dictionary of English v.0.48:
Retroflex \Re"tro*flex\, Retroflexed \Re"tro*flexed\, a. [Pref. retro- + L. flectere, flexum, to bend, to turn.] Reflexed; bent or turned abruptly backward. [1913 Webster]WordNet (r) 3.0 (2006):
retroflexed adj 1: bent or curved backward [syn: retroflex, retroflexed]