blackball: Meaning and Definition of

black•ball

1. to vote against (a candidate, applicant, etc.).
2. to exclude socially; ostracize: The whole town blackballed them.
3. to reject (a candidate) by placing a blackball in the ballot box.

1. a negative vote, esp. in deciding on an applicant or candidate.
2. a black ball placed in a ballot box signifying a negative vote.