to vote against (a candidate, applicant, etc.).

to exclude socially; ostracize

The whole town blackballed them.

to reject (a candidate) by placing a blackball in the ballot box.

a negative vote, esp. in deciding on an applicant or candidate.

a black ball placed in a ballot box signifying a negative vote.

verb

ban , blacklist , debar , exclude , ostracize , oust , reject , repudiate , snub , veto , negative , turn down , boycott , shut out , banish , bar , expel , shun