sand grouse vs sandgrouse

sand grouse and sandgrouse both are nouns.

Word	Noun	Adjective	Verb	Adverb
sand grouse	Yes	No	No	No
sandgrouse	Yes	No	No	No

As nouns, sand grouse and sandgrouse are synonyms defined as:

sand grouse and sandgrouse: pigeon-like bird of arid regions of the Old World having long pointed wings and tail and precocial downy young

sand grouse (noun)	sandgrouse (noun)
pigeon-like bird of arid regions of the Old World having long pointed wings and tail and precocial downy young	pigeon-like bird of arid regions of the Old World having long pointed wings and tail and precocial downy young