馬尾

Noun

 * 1) horse's tail
 * 2) ponytail hairstyle

Etymology 1
May be from compound. The, so a borrowing from no earlier than the.

Noun

 * 1) a horsetail
 * 2) horsehair, specifically from the tail
 * 3)  cauda equina

Etymology 2
Apparently derived from, , as horsehair was often used to make this.

The kanji are.

Noun

 * 1) horsehair, specifically from the tail