breeches vs knickers

breeches and knickers both are nouns.

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

As nouns, breeches and knickers are synonyms defined as:

breeches and knickers: (used in the plural) trousers ending above the knee

Other synonyms of breeches include knee breeches, knee pants, knickerbockers.

breeches (noun)	knickers (noun)
(used in the plural) trousers ending above the knee	(used in the plural) underpants worn by women
	(used in the plural) trousers ending above the knee