Enter a clue or pattern or both:
The Clue
Antiknock fluids (6 letter answer)
The Answer
ETHYLS
Tags
Notes
The answer ETHYLS is so rare that it appears less than once every 2500 puzzles.
Definition
ETHYL as a noun:
1. (ethyl, ethyl group, ethyl radical) = the univalent hydrocarbon radical C2H5 derived from ethane by the removal of one hydrogen atom