Sideburns and Sideburn

Sideburn and sideburns are semantically related in threadlike growth on animate being topic. In some cases you can use "Sideburn" instead a noun "Sideburns".

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).

Sideburns and sideburn are semantically related in hair topic. You can use "Sideburns" instead a noun "Sideburn", if it concerns topics such as beard.