noun
Describes hair that has come loose or is messy, often with a slightly poetic or literary feel.
風でほつれ髪が顔にかかった。
My unkempt hair blew into my face in the wind.
彼女はほつれ髪を手でかき上げた。
She pushed back her disheveled hair with her hand.
Compound of ほつれ (from verb 解れる 'to become untangled') + 髪 'hair'. The exact historical derivation is straightforward.