WordNet sense 1 (United States composer of avant-garde music (1912-1992)):

John Cage, John Milton Cage Jr.

WordNet sense 2 (an enclosure made or wire or metal bars in which birds or animals can be kept):

coop, coop

WordNet sense 3 (a movable screen placed behind home base to catch balls during batting practice):

batting cage

WordNet sense 4 (confine in a cage):

cage in