不遗余力 bù yí yú lì

DEFINITIONS

  1. to spare no pains or effort (idiom); to do one's utmost

CHARACTERS

不 bù
HSK 1
no, not; un-; negative prefix
遗 yí
HSK 5
lose; articles lost; omit
余 yú
HSK 5
I, my, me; surname; surplus
力 lì
HSK 3
power, capability, influence