pigeon keeping vs hobby

pigeon keeping and hobby both are nouns.

Word	Noun	Adjective	Verb	Adverb
pigeon keeping	Yes	No	No	No
hobby	Yes	No	No	No

As nouns, hobby is a hypernym of pigeon keeping; that is, hobby is a word with a broader meaning than pigeon keeping:

Other hypernyms of pigeon keeping include avocation, by-line, pursuit, sideline, spare-time activity.

pigeon keeping (noun)	hobby (noun)
the art and science of breeding domestic pigeons.	an auxiliary activity
	small Old World falcon formerly trained and flown at small birds
	a child's plaything consisting of an imitation horse mounted on rockers; the child straddles it and pretends to ride