verb

1. To rub hard; to wash with rubbing; usually, to rub with a wet brush, or with something coarse or rough, for the purpose of cleaning or brightening

   “to scrub a floor”

2. To rub anything hard, especially with a wet brush; to scour

3. To be diligent and penurious

   “to scrub hard for a living”

Synonyms: seek

noun

1. An act of cleaning in which something is scrubbed.

2. The removal of impurities from gas.