'Sheath' definitions:

Definition of 'sheath'

From: WordNet
noun
A protective covering (as for a knife or sword)
noun
An enveloping structure or covering enclosing an animal or plant organ or part [syn: sheath, case]
noun
A dress suitable for formal occasions [syn: cocktail dress, sheath]

Definition of 'Sheath'

From: GCIDE
  • Sheath \Sheath\, n. [OE. schethe, AS. sc[=ae][eth], sce['a][eth], sc[=e][eth]; akin to OS. sk[=e][eth]ia, D. scheede, G. scheide, OHG. sceida, Sw. skida, Dan. skede, Icel. skei[eth]ir, 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. [1913 Webster]
  • The dead knight's sword out of his sheath he drew. --Spenser. [1913 Webster]
  • 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) (Zool.) One of the elytra of an insect. [1913 Webster]
  • 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. [1913 Webster]

Synonyms of 'sheath'

From: Moby Thesaurus