step rocket vs booster

step rocket and booster both are nouns.

Word	Noun	Adjective	Verb	Adverb
step rocket	Yes	No	No	No
booster	Yes	No	No	No

step rocket (noun)	booster (noun)
a rocket having two or more rocket engines (each with its own fuel) that are fired in succession and jettisoned when the fuel is exhausted	an additional dose that makes sure the first dose was effective
	the first stage of a multistage rocket
	an amplifier for restoring the strength of a transmitted signal
	a thief who steals goods that are in a store
	someone who is an active supporter and advocate
	a person who backs a politician or a team etc.