from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A ramjet airplane engine designed for hypersonic flight that burns fuel in the supersonic airstream produced by the plane.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A jet engine capable of propelling an aircraft at hypersonic speeds; combustion of the fuel/air mixture occurs at supersonic speeds
s(upersonic) + c(ombustion) + ramjet.(American Heritage® Dictionary of the English Language, Fourth Edition)
Supersonic combustion + ramjet (Wiktionary)