Source : Webster's Revised Unabridged Dictionary (1913)

Scourer \Scour"er\, n.
   1. One who, or that which, scours.

   2. A rover or footpad; a prowling robber.

            In those days of highwaymen and scourers.
                                                  --Macaulay.

Source : WordNet®

scourer
     n 1: someone who cleanses by scouring
     2: someone who travels widely and energetically; "he was a
        scourer of the seven seas"