britches vs breeches

britches and breeches both are nouns.

Word	Noun	Adjective	Verb	Adverb
britches	Yes	No	No	No
breeches	Yes	No	No	No

As nouns, breeches is a hypernym of britches; that is, breeches is a word with a broader meaning than britches:

Other hypernyms of britches include knee breeches, knee pants, knickerbockers, knickers.

britches (noun)	breeches (noun)
(used in the plural) informal term for breeches	(used in the plural) trousers ending above the knee