bimbo; airhead beauty
A derogatory term for a woman whose attractiveness is seen as her only quality, implying lack of intelligence. Sensitive and potentially offensive; used in casual or critical contexts.
Some people say she's just a bimbo, but she's actually very smart.
The heroine of that movie is portrayed as an airhead beauty.
Compound of 白痴 (はくち, 'idiocy') and 美 (び, 'beauty'). The exact origin is uncertain, but it likely emerged as a slang term in modern Japanese.