Source : WordNet®

retroflection
     n 1: a turning or tilting backward of an organ or body part;
          "retroversion of the uterus" [syn: {retroversion}, {retroflexion}]
     2: an articulatory gesture made by turning the tip of the
        tongue back against the roof of the mouth [syn: {retroflexion}]
     3: the act of bending backward [syn: {retroflexion}]