scavenge

verb4

1. •
   To collect and remove refuse, or to search through refuse, carrion, or abandoned items for useful material.

   • We scavenged a couple of old beer cans for our art project.
   • They had to scavenge the forest for firewood.
2. •
   To feed on carrion or refuse.
3. •
   To remove unwanted material from something, especially to purify molten metal by removing impurities.
4. •
   To expel the exhaust gases from the cylinder of an internal combustion engine, and draw in air for the next cycle.