expulsion vs propulsion

expulsion and propulsion both are nouns.

Word	Noun	Adjective	Verb	Adverb
expulsion	Yes	No	No	No
propulsion	Yes	No	No	No

As nouns, propulsion is a hypernym of expulsion; that is, propulsion is a word with a broader meaning than expulsion:

Other hypernyms of expulsion include actuation.

expulsion (noun)	propulsion (noun)
the act of expelling or projecting or ejecting	the act of propelling
the act of forcing out someone or something	a propelling force
squeezing out by applying pressure