The Collaborative International Dictionary of English v.0.48:

Scavenge \Scav"enge\, v. t.
   To cleanse, as streets, from filth. --C. Kingsley.
   [1913 Webster]

   2. to salvage (usable items or material) from discarded or
      waste material.
      [PJC]

   3. To remove (burned gases) from the cylinder after a working
      stroke.
      [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Scavenge \Scav"enge\, v. i. (Internal-combustion Engines)
   To remove the burned gases from the cylinder after a working
   stroke; as, this engine does not scavenge well.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

scavenge
    v 1: clean refuse from; "Scavenge a street"
    2: collect discarded or refused material; "She scavenged the
       garbage cans for food" [syn: salvage, scavenge]
    3: feed on carrion or refuse; "hyenas scavenge"
    4: remove unwanted substances from [syn: scavenge, clean]

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "scavenge":
   bleach, bowdlerize, clean, clean out, clean up, cleanse, clear out,
   delouse, depurate, deterge, dry-clean, dust, dust off, expurgate,
   freshen, lustrate, purge, purify, reform, spruce, steam-clean,
   sweep out, sweeten, tidy, whiten, wipe, wipe off, wipe out,
   wipe up