It is a topknot. The chonmage is the topknot worn for daily ware. The highest ranking Yokozuna wear the gingko leaf.
The hair style depends on the rank of the sumo. The lowest ranks have no knot. Conmage topknot is for the makushita. The highest ranks wear it in a style known as the ginko leaf.
topknot?
A comb.
It is called a comb.
The decorative bow or chignon on the top of the head is commonly known as a "topknot" or "topknot hairstyle." It is a popular hairstyle that involves gathering the hair at the crown of the head and tying it into a bun or knot.
It is called a topknot.
sierra hunter
Lets hope we're talking hairstyles here. I would translate 髷 (mage) as "topknot" unless the context indicate a woman in which case I might use "chignon" if I thought the reader knew what such a thing was. Since "mage" is usually associated with sumo wrestlers (oicho-mage) or Edo period folk (chon-mage) its hard top imagine such a context. So unless you really want to challenge the reader I'd suggest sticking to topknot.
In Japanese, there is no visible indication, it is determined by the context. He was a sumo wrestler. There were ten sumo in that stable.
What English-speakers think of when they say "sumo" (i.e. heavyset men wrestling) is also called "sumo" in Japanese. Basically, sumo is sumo!
Sumo is a Japanese sport. There are Chinese sumo wrestlers.