丸髷

プログレッシブ和英中辞典(第4版)

まるまげ【丸^×髷】

a Japanese hairdo with an oval chignon [ʃíːnjɑn|-njɔːn] toward the back of the head (once commonly worn by a married woman)

丸まげに結う
do up one's hair in 「an oval chignon [a round knot]

出典　小学館「プログレッシブ和英中辞典(第4版)」