| Noun | 1. | blackball - the act of excluding someone by a negative vote or vetoexpulsion, riddance, ejection, exclusion - the act of forcing out someone or something; "the ejection of troublemakers by the police"; "the child's expulsion from school" | |
| Verb | 1. | blackball - expel from a community or group | |
| 2. | blackball - vote against; refuse to endorse; refuse to assent; "The President vetoed the bill" | |