1) Gluttonous 2) Thrifty 1) Thrifty 2) Two-stroke engine technology 
[automotive] In automotive usage, scavenging is the process of pushing exhausted gas-charge out of the cylinder and drawing in a fresh draught of air or fuel/air mixture for the next cycle. This process is essential in having a smooth-running internal combustion engine. If scavenging is incomplete, the following stroke will begin with a mix...
• (n.) Act or process of expelling the exhaust gases from the cylinder by some special means, as, in many four-cycle engines, by utilizing the momentum of the exhaust gases in a long exhaust pipe.
See leaching. 
Scav'eng·ing present participle & verbal noun of Scavenge . Hence, noun (Internal-combustion Engines) Act or process of expelling the exhaust gases from the cylinder by some special means, as, in many four-cycle engines, by utilizing the momentum of the exhaust gas...
inertia-caused movement of gases through cylinder and exhaust system of a two-stroke cycle or four-stroke cycle engine.
[adj] - searching for and salvaging anything useful from discarded material 2. [adj] - searching for and feeding on decaying matter