swab (swabs plural & 3rd person present) (swabbing present participle) (swabbed past tense & past participle )
1 n-count A swab is a small piece of cotton wool used by a doctor or nurse for cleaning a wound or putting a substance on it.
2 verb If you swab something, you clean it using a wet cloth or a tool called a mop.
I noticed a lone man in the cafeteria swabbing the floor as I passed. V n