Word: 万无一失 (wànwúyīshī) Traditional: 萬無一失 万无一失 dictionary entry wànwúyīshī surefire Full dictionary entry for 万无一失 Example sentences using 万无一失 2 sentences, showing page 1 of 1. 没有人能保证万无一失。 Méiyǒu rén néng bǎozhèng wànwúyìshī. Nobody can guarantee that nothing will go wrong. 门窗都锁好了，应该万无一失了。 Ménchuāng dōu suǒ hǎole, yīnggāi wànwúyìshī le. The doors and windows are all locked, so it should be completely safe.