1. to vote against someone’s admission to a club or organization
2. to ostracize or boycott someone

1. plural of blackball: votes against admission or acts of ostracism

Examples

• The committee blackballs any candidate without proper references.
• He was blackballed from the country club after the scandal.
• The union blackballs companies that don’t meet safety standards.
• She received three blackballs and was denied membership.
• The actor was blackballed by Hollywood studios for years.
• Several blackballs prevented his entry into the exclusive society.
• They blackball anyone who violates the organization’s code of conduct.