A topknot is hair gathered and tied up in a bunch high on the head — what people often call a bun, but specifically one sitting up on top rather than low at the back. Anyone can wear one. It is what you do with your hair to get it off your neck when you are hot, cooking, cleaning, or working out, and it is also a deliberate style. The word carries some history with it too: the tied knot of hair worn by samurai and sumo wrestlers in Japan, and by men in old Korea and China, is called a topknot in English. Birds have them as well — a topknot can mean the tuft of feathers standing up on a bird's head, like a cockatoo's. The word feels a little old-fashioned and a little affectionate in everyday English; a young person today is much more likely to say 'bun' or 'man bun' about their own hair. It is a countable noun, and you 'wear' or 'tie' one, or 'put your hair up in a topknot'.

（頭頂的）丸子頭、髮髻；（日本武士的）髮髻；（鳥的）冠羽