retractile

形容词 retractile:

1. capable of retraction; capable of being drawn back

1. A cat's claws are retractile.
   猫的爪能缩回。

re.trac.tile

adj.（形容词）
That can be drawn back or in:
能缩回或缩进的：
例句：
the retractile claws of a cat.
猫的能缩回的瓜子

【引伸】
re.tractil.ity