antbird vs ant bird

antbird and ant bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
antbird	Yes	No	No	No
ant bird	Yes	No	No	No

As nouns, antbird and ant bird are synonyms defined as:

antbird and ant bird: any of various dull-colored South American birds that feeding on ants some following army ant swarms

antbird (noun)	ant bird (noun)
any of various dull-colored South American birds that feeding on ants some following army ant swarms	any of various dull-colored South American birds that feeding on ants some following army ant swarms