search for and collect (anything usable) from discarded waste

people sell junk scavenged from the garbage

the city dump where the squatters scavenge to survive

remove (combustion products) from an internal combustion engine cylinder on the return stroke of the piston

solid lead deposits of combustion would be scavenged from the engine

combine with and remove (molecules, groups, etc.) from a particular medium

chlorine molecules can scavenge ozone at a very fast rate