Sheath

n.	1.	A case for the reception of a sword, hunting knife, or other long and slender instrument; a scabbard. The dead knight's sword out of his sheath he drew. - Spenser.
	2.	(Bot.) Any sheathlike covering, organ, or part. Medullary sheath (Anat.) See under Medullary. Primitive sheath (Anat.) See Neurilemma. Sheath knife a knife with a fixed blade, carried in a sheath. Sheath of Schwann (Anat.) See Schwann's sheath.

Noun	1.	sheath - a protective covering for a knife or sword
	2.	sheath - an enveloping structure or covering enclosing an animal or plant organ or part Synonyms: case
	3.	sheath - a dress suitable for formal occasions Synonyms: cocktail dress

Leatherette, Leatheroid, case, casing, coat, cuticle, dermis, encasement, fell, fleece, flesh, fur, furring, hide, imitation fur, imitation leather, integument, jacket, leather, leather paper, outer layer, outer skin, pelt, peltry, rawhide, rind, sheathing, skin, skins, tegument, vair