noun
frizz; flyaway hair; idiot hair
Colloquial term for short, unruly tufts of hair that stick up or curl away from the rest of the hair, often noticed in the morning or in humid weather. The literal 'idiot hair' is a playful, self-deprecating expression.
朝起きたらアホ毛がすごくて、なかなか直らなかった。
When I woke up, my flyaway hairs were terrible and wouldn't settle down.
湿気のせいでアホ毛が目立つ。
My frizz stands out because of the humidity.
くせ毛 is a general term for naturally wavy or curly hair, whereas アホ毛 describes isolated flyaway strands.
Compound of アホ (fool, idiot) and 毛 (hair), literally 'idiot hair'. The term humorously personifies unruly hairs as acting foolishly by not lying flat.