Meaning of wàn yī:
wàn yī
万一
Adverb
just in case
Nǐ yīnggāi zhǔnbèi yī gè jìhuà, yǐ fáng wànyī.
你应该准备一个计划，以防万一。
You should prepare a plan just in case.
Conjunction
if by any chance
wàn yī míngtiān xià yǔ, wǒmen jiù dài zài jiālǐ.
万一明天下雨，我们就待在家里。
If by any chance it rains tomorrow, we will stay at home.
Noun
contingency
Wǒmen yīnggāi tíqián zuò hǎo jìhuà, yǐ fáng wànyī.
我们应该提前做好计划，以防万一。
We should plan ahead in case of any contingency.
