knickers vs knee pants

knickers and knee pants both are nouns.

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

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

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

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

knickers (noun)	knee pants (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