1. Plural of bally; a marble or ball used in games, especially in children's games.
Usage: informal; chiefly British
2. Plural of bally; testicles (vulgar slang).
Usage: vulgar; slang; chiefly British

Examples

• The children played with their ballies in the schoolyard.
• He lost his favorite ballies during the marble game.
• The bag contained dozens of colorful ballies for the tournament.