fuel system vs throttle

fuel system and throttle both are nouns.

Word	Noun	Adjective	Verb	Adverb
fuel system	Yes	No	No	No
throttle	Yes	No	Yes	No

fuel system (noun)	throttle (noun)
equipment in a motor vehicle or aircraft that delivers fuel to the engine	a valve that regulates the supply of fuel to the engine
	a pedal that controls the throttle valve

fuel system (verb)	throttle (verb)
	reduce the air supply
	place limits on (extent or amount or access)
	kill by squeezing the throat of so as to cut off the air