'Juè tóu juè nǎo' is a reduplicative, four-character adjective describing someone—typically a child or young person—who is stubbornly headstrong in a way that’s endearing or childish rather than malicious. The repetition of 倔 (juè, 'obstinate') emphasizes the intensity of the trait, while 头 (tóu, 'head') and 脑 (nǎo, 'brain') metaphorically point to the source of this willfulness—thinking and acting with inflexible determination, often without considering consequences or others’ advice.

This term carries a gentle, affectionate tone; it’s rarely used critically for adults and almost never for serious defiance. It appears frequently in family contexts, storytelling, or light-hearted criticism—e.g., when a toddler refuses to wear shoes or a teenager insists on choosing their own clothes despite parental suggestions. It evokes innocence and immaturity more than arrogance or rebellion.