scavenger (n.) Look up scavenger at Dictionary.com
originally "person hired to remove refuse from streets," from Middle English scawageour (late 14c.), London official in charge of collecting tax on goods sold by foreign merchants, from Anglo-French scawager, from scawage "toll or duty on goods offered for sale in one's precinct" (c.1400), from Old North French escauwage "inspection," from a Germanic source (cf. Old High German scouwon, Old English sceawian "to look at, inspect," see show (v.)). With intrusive -n- (c.1500) as in harbinger, passenger, messenger. Extended to animals 1590s. Scavenger hunt is attested from 1940.