Category:Sheath

Sheath, n. Etym: [oe. schethe, as. scæedh, sceáedh, sceedh; akin to Os. skeedhia, d. scheede, g. scheide, ohg. sceida, sw. skida, dan. Skede, icel. skeiedhir, pl., and to e. shed, v.t., originally Meaning, to separate, to part. See shed.]

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. Any sheathlike covering, organ, or part. Specifically: (a) (bot.) The base of a leaf when sheathing or investing a stem or Branch, as in grasses. (b) (zoöl.) One of the elytra of an insect. 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.