birdfeeder vs bird feeder

birdfeeder and bird feeder both are nouns.

Word	Noun	Adjective	Verb	Adverb
birdfeeder	Yes	No	No	No
bird feeder	Yes	No	No	No

As nouns, birdfeeder and bird feeder are synonyms defined as:

birdfeeder and bird feeder: an outdoor device that supplies food for wild birds

Other synonyms of birdfeeder include feeder.

birdfeeder (noun)	bird feeder (noun)
an outdoor device that supplies food for wild birds	an outdoor device that supplies food for wild birds