from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A substance, such as tetraethyl lead, added to gasoline to reduce engine knock.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. of an additive added to petroleum/gasoline to reduce the occurrence of engine knock.
- n. Such a substance, usually tetraethyl lead (also MMT, MTBE and ethanol)
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. any of various compounds that are added to gasoline to reduce engine knocking
- adj. suppressing or eliminating engine knock in combustion engines
anti- + knock (Wiktionary)