knickers vs knee breeches

knickers and knee breeches both are nouns.

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

As nouns, knickers and knee breeches are synonyms defined as:

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

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

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