Cage/keɪdʒ/ Definition 1 of 4Pro Tip 1/3Literal Use Use 'cage' to refer to physical enclosures with bars; specifically for confining animals. The zoo installed new cages for the monkeys. Pro Tip 2/3Negative Feelings A cage usually implies captivity and lack of freedom, which can evoke sympathy for caged animals. Seeing birds in a tiny cage makes me sad. Pro Tip 3/3Material Notice Cages are often made of metal, but you might find wooden or plastic ones for smaller pets. She bought a wooden cage for her parrot.