sideburns

The word was reformed from "burnside," itself named after American Army general Ambrose Burnside (1824–1881), who was noted for his distinctive facial hair.

Originally the style was called "burnside," after the general's surname, but over time the two parts of the word were swapped to produce "sideburns."

It shares its origin story with "burnside," the earlier term for the same style, named for the same man.