cage vs birdcage

cage and birdcage both are nouns.

Word	Noun	Adjective	Verb	Adverb
cage	Yes	No	Yes	No
birdcage	Yes	No	No	No

As nouns, birdcage is a hyponym of cage; that is, birdcage is a word with a more specific, narrower meaning than cage:

cage: an enclosure made or wire or metal bars in which birds or animals can be kept
birdcage: a cage in which a bird can be kept

Other hyponyms of cage include hutch, squirrel cage.

cage (noun)	birdcage (noun)
an enclosure made or wire or metal bars in which birds or animals can be kept	a cage in which a bird can be kept
the net that is the goal in ice hockey
a movable screen placed behind home base to catch balls during batting practice
something that restricts freedom as a cage restricts movement

cage (verb)	birdcage (verb)
confine in a cage