n.1. A structure for confining birds or animals, enclosed on at least one side by a grating of wires or bars that lets in air and light.
2. A barred room or fenced enclosure for confining prisoners.
3. An enclosing openwork structure: placed a protective cage over the sapling; a bank teller's cage.
4. A skeletal support, as for a building; a framework.
5. An elevator car.
6. a. Baseball A batting cage.
b. Sports A goal, as in hockey or soccer, made of a net attached to a frame.