万无一失 Traditional 萬無一失 wàn wú yī shī 🔊 surefire; absolutely safe (idiom) HSK 7–9 + Keep this word Meanings wàn wú yī shī 萬無一失 surefire; absolutely safe (idiom) Its characters 万wànten thousandHSK 2无wúnot to haveHSK 4一yīoneHSK 1失shīto lose