expulsion vs blackball

expulsion and blackball both are nouns.

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

As nouns, blackball is a hyponym of expulsion; that is, blackball is a word with a more specific, narrower meaning than expulsion:

Other hyponyms of expulsion include defenestration, deportation, ostracism, barring, ouster, ousting.

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

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