SWOB

A small piece of soft, absorbent material, such as gauze, used to clean wounds, apply medicine, or take samples of body fluids. Often attached to a stick or wire to aid access.

A sample taken with a swab (piece of absorbent material).

A piece of material used for cleaning or sampling other items like musical instruments or guns.

To use a swab on something, or clean something with a swab.

"swab the deck of a ship"