What does "cage" mean?

Cage: A place of confinement for malefactors Shak. Stone walls do not a prison make, Nor iron bars a cage. Lovelace.

Additional senses

  1. 2.(Carp.) An outer framework of timber, inclosing something within it; as the cage of a staircase. Gwilt.
  2. 3.(Mach.) (a) A skeleton frame to limit the motion of a loose piece, as a ball valve. (b) A wirework strainer, used in connection with pumps and pipes.
  3. 4.The box, bucket, or inclosed platform of a lift or elevator; a cagelike structure moving in a shaft.
  4. 5.(Mining) The drum on which the rope is wound in a hoisting whim.
  5. 6.(Baseball) The catcher's wire mask.
  6. 7.To confine in, or as in, a cage; to shut up or confine. "Caged and starved to death." Cowper.

Sources