伸縮自如的,縮回的,收縮的
Retractile \Re*tract"ile\, a. [Cf. F. -r['e]tractile.] (Physiol.) Capable of retraction; capable of being drawn back or up; as, the claws of a cat are retractile.
retractile adj : capable of retraction; capable of being drawn back; "cats have retractile claws" [ant: {nonretractile}]