1650s, "mop made of rope or yarn," from swabber (c.1600) "mop for cleaning a ship's deck," from Dutch zwabber, akin to West Frisian swabber "mop," from Proto-Germanic *swab-, perhaps of imitative origin. Non-nautical meaning "anything used for mopping up" is from 1787. Slang meaning "a sailor" first attested 1798, from swabber "member of a ship's crew assigned to swab decks" (1590s), which by 1609 was being used in a broader sense of "one who behaves like a low-ranking sailor."
1719, possibly from swab (n.). Related: Swabbed; swabbing.
A small piece of absorbent material attached to the end of a stick or wire and used for cleansing or applying medicine.
A specimen of mucus or other material removed with a swab.
A sailor, esp a Navy seaman: better fitting dress uniforms for the hard-to-fit doughboy or swabbie
[1798+; probably fr the characteristic activity of using swabs for cleaning the decks and other features of a ship]