also: ブルーネット
noun
brunette; brown-haired woman or girl
Usually refers to a woman or girl with dark brown hair. In Japanese it is a specific foreign-style description and is less everyday than expressions such as 茶色い髪 or 茶髪.
写真の中央にいるブルネットが私の姉です。
The brunette in the middle of the photo is my older sister.
noun
brown-skinned or brown-eyed woman or girl
A less common descriptive use referring to complexion or eye color rather than only hair color; context usually needs to make the intended feature clear.
その小説では、ヒロインは褐色の肌と茶色の目を持つブルネットとして描かれている。
In that novel, the heroine is portrayed as a brunette with brown skin and brown eyes.