D defs.my
Entry 2 senses Webster, 1913

Sheath

/shēth/ · IPA /ʃiθ/
01 n. A case for the reception of a sword, hunting knife, or other long and slender instrument; a scabbard.
  1. 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. 2.
    Any sheathlike covering, organ, or part.(Bot.)
Phrases & compounds
Medullary sheath — See under Medullary.
Primitive sheath — See Neurilemma.
Sheath knife — a knife with a fixed blade, carried in a sheath.
Sheath of Schwann — See Schwann's sheath.