adj. not able to be drawn into the main body; -- of claws and other extensile parts of animals or objects; as, a bear's claws, unlike a cat's, are nonretractile. Opposite of retractile. [ WordNet 1.5 ]
a. [ Cf. F. -rétractile. ] (Physiol.) Capable of retraction; capable of being drawn back or up; as, the claws of a cat are retractile. [ 1913 Webster ]