萬無一失 wàn wú yī shī

DEFINITIONS

  1. surefire; absolutely safe (idiom)

CHARACTERS

萬 wàn ten thousand; innumerable
無 wú negative, no, not; lack, have no
一 yī
HSK 1
one; a, an; alone
失 shī
HSK 4
lose; make mistake, neglect