blackball vs shoot down

blackball is a noun but shoot down is not a noun.

Word	Noun	Adjective	Verb	Adverb
blackball	Yes	No	Yes	No
shoot down	No	No	Yes	No

As verbs, shoot down is a hyponym of blackball; that is, shoot down is a word with a more specific, narrower meaning than blackball:

Other hyponyms of blackball include defeat, kill, vote down, vote out.

blackball (noun)	shoot down (noun)
the act of excluding someone by a negative vote or veto

blackball (verb)	shoot down (verb)
expel from a community or group	shoot at and force to come down
vote against; refuse to endorse; refuse to assent	move quickly and violently
	thwart the passage of