noun
kinky hair; frizzy hair; unruly hair; curly hair
Refers to hair that is naturally curly, wavy, or difficult to manage. Often used for hair that is not straight, regardless of curl tightness.
彼女は癖毛をストレートに伸ばした。
She straightened her unruly hair.
湿気が多い日は癖毛が広がりやすい。
On humid days, frizzy hair tends to expand.
Compound of 癖 (くせ, 'habit; tendency') and 毛 (け, 'hair'), literally 'habit hair'.