traditional Japanese women's hairstyle
Refers to the classical, often elaborate hairstyles worn by Japanese women, especially associated with kimono, geisha, and bridal attire.
花嫁は美しい日本髪を結っていた。
The bride wore a beautiful traditional Japanese hairstyle.
日本髪 is the general category of traditional Japanese hairstyles, while 島田 refers to one specific style within that category.
Compound of 日本 (Nihon, 'Japan') and 髪 (kami, 'hair'). The reading がみ is a rendaku form of かみ.