Sheath

(n.) A case for the reception of a sword, hunting knife, or other long and slender instrument; a scabbard.

Sheath - Other Definitions

(n.) A case for the reception of a sword, hunting knife, or other long and slender instrument; a scabbard.
(n.) Any sheathlike covering, organ, or part.
(n.) The base of a leaf when sheathing or investing a stem or branch, as in grasses.
(n.) One of the elytra of an insect.
(imp. & p. p.) of Sheathe
(a.) Povided with, or inclosed in, sheath.
(a.) Invested by a sheath, or cylindrical membranaceous tube, which is the base of the leaf, as the stalk or culm in grasses; vaginate.