ostracise vs blackball

ostracise is not a noun while blackball is a noun.

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

As verbs, ostracise and blackball are synonyms defined as:

Other synonyms of ostracise include ban, banish, cast out, ostracize, shun.

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

ostracise (verb)	blackball (verb)
avoid speaking to or dealing with	expel from a community or group
expel from a community or group	vote against; refuse to endorse; refuse to assent