blackball vs expulsion

blackball and expulsion both are nouns.

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

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

Other hypernyms of blackball include ejection, exclusion, riddance.

blackball (noun)	expulsion (noun)
the act of excluding someone by a negative vote or veto	the act of expelling or projecting or ejecting
	the act of forcing out someone or something
	squeezing out by applying pressure

blackball (verb)	expulsion (verb)
expel from a community or group
vote against; refuse to endorse; refuse to assent