scavenger

noun

1. an animal or other organism that feeds on dead organic matter.
2. a person who searches through and collects items from discarded material.
3. a street cleaner.
4. Chemistry. a chemical that consumes or renders inactive the impurities in a mixture.

noun

1. a person who collects things discarded by others
2. any animal that feeds on decaying organic matter, esp on refuse
3. a substance added to a chemical reaction or mixture to counteract the effect of impurities
4. a person employed to clean the streets

n.1540s, 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.)). It has come to be regarded as an agent noun in -er, but the verb is a late back-formation from the noun. With intrusive -n- (c.1500) as in harbinger, passenger, messenger. Extended to animals 1590s. Scavenger hunt is attested from 1937.

1. An animal that feeds on dead organisms, especially a carnivorous animal that eats dead animals rather than or in addition to hunting live prey. Vultures, hyenas, and wolves are scavengers.