red grouse vs moorbird

red grouse and moorbird both are nouns.

Word	Noun	Adjective	Verb	Adverb
red grouse	Yes	No	No	No
moorbird	Yes	No	No	No

As nouns, red grouse and moorbird are synonyms defined as:

red grouse and moorbird: reddish-brown grouse of upland moors of Great Britain

Other synonyms of red grouse include Lagopus scoticus, moor-bird, moorfowl, moorgame.

red grouse (noun)	moorbird (noun)
reddish-brown grouse of upland moors of Great Britain	reddish-brown grouse of upland moors of Great Britain