A rooster is a male chicken. If the cute yellow baby chick grows up to crow loudly first thing every morning, this cutie is probably a rooster. The word rooster is an American invention, inspired by the rooster's habit of roosting, or standing up on a perch while sleeping or while on the lookout for danger. In a flock of birds, the rooster's job is to defend the chickens and their nests from predators and other roosters. Minimal cursor pack with Rooster pointer.