flyweight
- n weighs no more than 115 pounds
- n an amateur boxer who weighs no more than 112 pounds
flywheel
- n regulator consisting of a heavy wheel that stores kinetic energy and smooths the operation of a reciprocating engine
fm
- n modulation of the frequency of the (radio) carrier wave
- n a radioactive transuranic metallic element produced by bombarding plutonium with neutrons