sideburn vs burnside

sideburn and burnside both are nouns.

Word	Noun	Adjective	Verb	Adverb
sideburn	Yes	No	No	No
burnside	Yes	No	No	No

As nouns, sideburn and burnside are synonyms defined as:

sideburn and burnside: 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 sideburn include mutton chop, side-whiskers.

sideburn (noun)	burnside (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)