sheath

noun

ˈshēth 

plural sheaths ˈshēt͟hz  ˈshēths 

1

: a case for a blade (as of a knife)

2

: an investing cover or case of a plant or animal body or body part: such as

a

: the tubular fold of skin into which the penis of many mammals is retracted

b(1)

: the lower part of a leaf when surrounding the stem

(2)

: an ensheathing spathe

3

: any of various covering or supporting structures that resemble in appearance or function the sheath of a blade: such as

a

: sheathing sense 2

b

: a woman's close-fitting dress that is usually worn without a belt

c

British : condom sense 1

Synonyms

• armor
• capsule
• case
• casing
• cocoon
• cover
• covering
• encasement
• housing
• hull
• husk
• jacket
• pod
• shell

Examples of sheath in a Sentence

the sheath of a sword

a piece of wire covered with a plastic sheath

Recent Examples on the Web

Among the evidence police collected: bloody shoeprints and fingerprints, a knife sheath and the suspect's hair collected from Gayle's shirt, hands and the floor. —Natalie Neysa Alund, USA TODAY, 24 Sep. 2024

The particular cells imaged here are precursors to oligodendrocytes, cells that produce myelin in the body, the substance that forms protective sheaths around nerve fibers. —Michael Franco, New Atlas, 21 Sep. 2024

Among the dead was Hugh de Cressingham, the king’s treasurer, whose corpse was reportedly flayed to make a sheath for Wallace’s sword. —Meilan Solly, Smithsonian Magazine, 11 Sep. 2024

Corticosteroid Injections Corticosteroids can be injected into the tendon sheath at the base of the affected finger. —Lana Barhum, Verywell Health, 14 Aug. 2024

Word History

Etymology

Middle English shethe, going back to Old English scǣþ, scēaþ (Northumbrian sceǣþ), scēþ, going back to Germanic *skaiþjō or *skaiþō (whence also Old Frisian skēthe "sheath," Old Saxon skēdia, skēthia, Old High German skeida, Old Icelandic skeiðir, plural), probably noun derivative of *skaiđan-/skaiþan- "to separate, divide" — more at shed entry 1

Note: The original meaning of the Germanic noun was presumably "something split, separated," i.e., two pieces that are split (literally or metaphorically) and that together held the blade; note that the Old Norse noun was plural (the singular skeið meant "weaver's reed, silver spoon").

First Known Use

before the 12th century, in the meaning defined at sense 1

Phrases Containing sheath

• medullary sheath
• myelin sheath
• sheath knife

Kids Definition

sheath

noun

ˈshēth 

plural sheaths ˈshēt͟hz 

ˈshēths

1

: a case for a blade (as of a knife)

2

: a covering especially of a body part that is like a sheath in form or use

Medical Definition

sheath

noun

ˈshēth 

plural sheaths ˈshēt͟hz  ˈshēths 

1

: an investing cover or case of a plant or animal body or body part: as

a

: the tubular fold of skin into which the penis of many mammals is retracted

b

: the connective tissue of an organ or part that binds together its component elements and holds it in place

2

: condom sense 1

sheathed adjective