side-whiskers vs sideburn

side-whiskers and sideburn both are nouns.

Word	Noun	Adjective	Verb	Adverb
side-whiskers	Yes	No	No	No
sideburn	Yes	No	No	No

As nouns, side-whiskers and sideburn are synonyms defined as:

side-whiskers and sideburn: facial hair that has grown down the side of a man's face in front of the ears (especially when the rest of the beard is shaved off)

Other synonyms of side-whiskers include burnside, mutton chop.

side-whiskers (noun)	sideburn (noun)
facial hair that has grown down the side of a man's face in front of the ears (especially when the rest of the beard is shaved off)	facial hair that has grown down the side of a man's face in front of the ears (especially when the rest of the beard is shaved off)