Wordnet 3.0
NOUN (2)
1. 
 someone who cleanses by scouring; 
2. 
 someone who travels widely and energetically; 
- Example: "he was a scourer of the seven seas"
The Collaborative International Dictionary of English v.0.48:
Scourer \Scour"er\, n.
   1. One who, or that which, scours.
      [1913 Webster]
   2. A rover or footpad; a prowling robber.
      [1913 Webster]
            In those days of highwaymen and scourers.
                                                  --Macaulay.
      [1913 Webster]
WordNet (r) 3.0 (2006):
scourer
    n 1: someone who cleanses by scouring
    2: someone who travels widely and energetically; "he was a
       scourer of the seven seas"