pouter pigeon vs pouter

pouter pigeon and pouter both are nouns.

Word	Noun	Adjective	Verb	Adverb
pouter pigeon	Yes	No	No	No
pouter	Yes	No	No	No

As nouns, pouter pigeon and pouter are synonyms defined as:

pouter pigeon and pouter: one of a breed of pigeon that enlarge their crop until their breast is puffed out

pouter pigeon (noun)	pouter (noun)
one of a breed of pigeon that enlarge their crop until their breast is puffed out	one of a breed of pigeon that enlarge their crop until their breast is puffed out
	someone with a habitually sullen or gloomy expression