sheath

American  

[sheeth] / ʃiθ /

noun

plural

sheaths

1. a case or covering for the blade of a sword, dagger, or the like.

2. any similar close-fitting covering or case.

3. a condom.

4. Biology. a closely enveloping part or structure, as in an animal or plant.

5. Botany. the leaf base when it forms a vertical coating surrounding the stem.

6. a close-fitting dress, skirt, or coat, especially an unbelted dress with a straight drape.

7. Electricity. the metal covering of a cable.

8. Electronics.

   1. the metal wall of a wave guide.

   2. a space charge formed by ions near an electrode in a tube containing low-pressure gas.

   3. the region of a space charge in a cathode-ray tube.

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verb (used with object)

1. to sheathe.

sheath British  

/ ʃiːθ /

noun

1. a case or covering for the blade of a knife, sword, etc

2. any similar close-fitting case

3. biology an enclosing or protective structure, such as a leaf base encasing the stem of a plant

4. the protective covering on an electric cable

5. a figure-hugging dress with a narrow tapering skirt

6. another name for condom

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verb

1. (tr) another word for sheathe

sheath Scientific  

/ shēth /

1. An enveloping tubular structure, such as the base of a grass leaf that surrounds the stem or the tissue that encloses a muscle or nerve fiber.

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Other Word Forms

• sheathless adjective
• sheathlike adjective
• sheathy adjective

Etymology

Origin of sheath

before 950; Middle English s ( c ) heth ( e ), Old English scēath; cognate with German Scheide; shed ²

Example Sentences

Calvin Klein, where Bessette worked before marrying JFK Jr., has a “90s Edit” on its website showcasing sheath dresses, white button-down shirts and other minimalist looks from the era.

From The Wall Street Journal • Apr. 7, 2026

The research showed that MS first targets the myelin sheath.

From Science Daily • Oct. 21, 2025

Frankly, Aidan’s behavior is far more concerning than Wyatt’s, a flag so big and red that Carrie could make a stunning sheath dress out of it.

From Los Angeles Times • Jul. 3, 2025

Investigators linked Kohberger to the murder through cell phone data, surveillance video, and DNA on a knife sheath at the crime scene.

From Salon • Jul. 2, 2025

One was for a spyglass, one for a whorly, whistling shell, and one for a fat red pocketknife in a sheath.

From "Nim’s Island" by Wendy Orr

Related Words

• covering