knickerbockers vs knee pants

knickerbockers and knee pants both are nouns.

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

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

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

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

knickerbockers (noun)	knee pants (noun)
(used in the plural) trousers ending above the knee	(used in the plural) trousers ending above the knee