What is "chonmage"

n. (context sumo English) the simple topknot worn by rikishi of the lower ranks, and by the higher ranks on informal occasions

The chonmage ( 丁髷, ちょんまげ) is a form of Japanese traditional haircut worn by men. It is most commonly associated with the Edo Period and samurai, and in recent times with sumo wrestlers. It was originally a method of using hair to hold a samurai helmet steady atop the head in battle, and became a status symbol among Japanese society.

A traditional Edo-era chonmage featured a shaved pate. The remaining hair, which was long, was oiled and tied into a small queue which was folded onto the top of the head in the characteristic topknot.