Source : Webster's Revised Unabridged Dictionary (1913)

Scrub \Scrub\ (skr[u^]b), v. t. [imp. & p. p. {Scrubbed}
   (skr[u^]bd); p. pr. & vb. n. {Scrubbing}.] [OE. scrobben,
   probably of Dutch or Scand. origin; cf. Dan. sckrubbe, Sw.
   skrubba, D. schrobben, LG. schrubben.]
   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; as, to scrub a floor, a doorplate.

Source : WordNet®

scrub
     adj : (of domestic animals) not selectively bred
     [also: {scrubbing}, {scrubbed}]

scrubbing
     n : the act of cleaning a surface by rubbing it with a brush and
         soap and water [syn: {scrub}, {scouring}]

scrub
     v 1: clean with hard rubbing; "She scrubbed his back" [syn: {scour}]
     2: wash thoroughly; "surgeons must scrub prior to an operation"
        [syn: {scrub up}]
     [also: {scrubbing}, {scrubbed}]

scrub
     n 1: dense vegetation consisting of stunted trees or bushes [syn:
           {chaparral}, {bush}]
     2: the act of cleaning a surface by rubbing it with a brush and
        soap and water [syn: {scrubbing}, {scouring}]
     [also: {scrubbing}, {scrubbed}]

scrubbing
     See {scrub}