brass balls

brass balls

1. vulgar slang Unwavering courage, resolve, or toughness. It takes brass balls to stand up to a bully like that. You've got to have brass balls if you're going to survive in this business.2. vulgar slang Excessive impudence, self-assurance, ego, or audacity. He's got some brass balls to talk to his boss like that.See also: ball, brass