摩頂放踵 [－顶－－]

Jyutping mo1 deng2 fong3 zung2
Pinyin mó dǐng fàng zhǒng

Definitions (CC-CEDICT)
  1. to rub one's head and heels (idiom); to slave for the benefit of others
  2. to wear oneself out for the general good