To envelop in a protective case.
To withdraw into such a case.
The silky protective case spun by the larvae of some insects in which they metamorphose, the pupa.
Any similar protective case, whether real or metaphorical.
To encase (something) with a protective covering.
To thrust (a sharp object like a sword, a claw, or a tusk) into something.
To put (something such as a knife or sword) into a sheath.
Of an animal: to draw back or retract (a body part) into the body, such as claws into a paw.