noun (n)

• a turning or tilting backward of an organ or body part(noun.state)

  Synonym:
  retroflection, retroversion
  

  source: wordnet30
• an articulatory gesture made by turning the tip of the tongue back against the roof of the mouth(noun.communication)

  Synonym:
  retroflection
  

  source: wordnet30
• the act of bending backward(noun.act)

  source: wordnet30
• The act of reflexing; the state of being retroflexed. Cf. Retroversion.(noun)

  source: webster1913