皮毛

fur / fur clothing / skin and hair / superficial / superficial knowledge

surname Pi

leather / skin / fur / CL:張|张[zhang1] / pico- (one trillionth) / naughty

surname Mao

hair / feather / down / wool / mildew / mold / coarse or semifinished / young / raw / careless / unthinking / nervous / scared / (of currency) to devalue or depreciate / classifier for Chinese fractional monetary unit ( = 角[jiao3] , = one-tenth of a yuan or 10 fen 分[fen1])

slight knowledge of sth / superficial acquaintance with a subject / a smattering