headgear vs stable gear

headgear and stable gear both are nouns.

Word	Noun	Adjective	Verb	Adverb
headgear	Yes	No	No	No
stable gear	Yes	No	No	No

As nouns, stable gear is a hypernym of headgear; that is, stable gear is a word with a broader meaning than headgear:

headgear: stable gear consisting of any part of a harness that fits about the horse's head
stable gear: gear for a horse

Other hypernyms of headgear include saddlery, tack.

headgear (noun)	stable gear (noun)
clothing for the head	gear for a horse
stable gear consisting of any part of a harness that fits about the horse's head
the hoist at the pithead of a mine