Sideburns (known colloquially as side-whiskers, or sideboards in the United Kingdom) are patches of facial hair grown on the sides of a man's face, in front of the ears. The term “sideburns” is a 19th century bastardization of the original burnsides, named after Ambrose Burnside, a man known for his unusual facial hairstyle that connected thick sideburns by way of a moustache but left the chin clean-shaven.
Sideburns are hardly restricted to any particular length or shape, and a number of variations can be found throughout history- they can be thin or wide, voluptuous or neatly-trimmed; be cropped flat, flare out, or end in a point; end at mid-ear or further down the jawline. The word 'Sideburns' is also a broad term that encompasses several other distinct types of facial hair, such as Mutton Chops and Friendly Mutton Chops. Mutton Chops are sideburns named for their mutton-like shape as they extend down to the corner of the mouth, while Friendly Mutton Chops connect both sideburns with a "friendly" moustache- a style of facial hair not unlike the one worn by Burnside himself.
Sideburns can be worn in combination with other styles of facial hair, such as the moustache or goatee, but once they extend from ear to ear via the chin they cease to be sideburns and become a beard, or chin curtain.
After the clean-shaven period of the eighteenth century, sideburns, like beards, began to grow in popularity during the early nineteenth century, a trend that eventually made its way to Japan. Nineteenth century sideburns were often far more extravagant than those seen today, appearing more along the lines of what we know as modern-day mutton chops. As with beards, sideburns went quickly out of fashion in the early twentieth century, but made a comeback in the 1960s and 1970s among the younger generation. Pointed sideburns, more specifically, became a symbol of the gay club scenes of San Francisco and Sydney, Australia. Because of their multifarious history, sideburns may be seen as either stuffily Victorian and ultra-conservative, or as a sign of 1970s-style rebelliousness. Today sideburns enjoy an intermediate level of popularity, though groups of sideburn and beard afficionados have formed and flourished with the introduction of the internet.
Indigenous men of Mexico, who shave their heads and wear their sideburns long, as well as Colombians, who wear their sideburns long and typically do not have any other facial hair, are said to be wearing "balcarrotas".