swab

¹ American  

[swob] / swɒb /

noun

1. a large mop used on shipboard for cleaning decks, living quarters, etc.

2. a bit of sponge, cloth, cotton, or the like, sometimes fixed to a stick, for cleansing the mouth of a sick person or for applying medicaments, drying areas, etc.

3. the material collected with a swab as a specimen for microscopic study.

4. a brush or wad of absorbent material for cleaning the bore of a firearm.

5. Slang. a sailor; swabby.

6. Slang. a clumsy fellow.

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verb (used with object)

swabbed, swabbing

1. to clean with or as if with a swab.

   to swab the decks.

2. to take up or apply, as moisture, with or as if with a swab.

   to swab soapy water from the decks.

3. to pass over a surface.

   to swab a mop over the decks.

Swab. ² American  

abbreviation

1. Swabia.

2. Swabian.

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swab British  

/ swɒb /

noun

1. med

   1. a small piece of cotton, gauze, etc, for use in applying medication, cleansing a wound, or obtaining a specimen of a secretion, etc

   2. the specimen so obtained

2. a mop for cleaning floors, decks, etc

3. a brush used to clean a firearm's bore

4. slang an uncouth or worthless fellow

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verb

1. (tr) to clean or medicate with or as if with a swab

2. to take up with a swab

Other Word Forms

• unswabbed adjective

Etymology

Origin of swab

First recorded in 1645–55; back formation from swabber

Explanation

If a pirate tells you to swab the deck, get out the mop! A swab is a piece of absorbent material on a stick, like a mop, but it can also be small, like a cotton swab used for cleaning ears. As a verb, to swab means to use a swab. So if you're a nurse assisting a surgeon, you might swab an incision, and if you're working on crime scene, you might swab the area for clues. On land, a swab is usually a small piece of cotton, but the original meaning of the noun was "mop used on a ship," and for a while it was also a popular derogatory term for a low-ranking sailor.

Example Sentences

Yet Jones didn’t instruct her to swab the plastic pill bag.

From The Wall Street Journal • Apr. 5, 2026

Olympics and beyond will be determined by a one-time genetics test through saliva, a cheek swab or a blood sample.

From Los Angeles Times • Mar. 30, 2026

The test requires screening through saliva, a cheek swab or a blood sample.

From Los Angeles Times • Mar. 26, 2026

Doctors typically swab a patient’s cervix in clinical settings to test for high-risk strains of the human papillomavirus, an infection that can cause cancer when left untreated, through Pap smears and HPV testing.

From The Wall Street Journal • Jan. 5, 2026

I sat on the side of the tub while Rosaleen dabbed my arm with a stinging icy swab.

From "The Secret Life of Bees" by Sue Monk Kidd

Related Words

• daub
• mop