万一 (Manichi) is a Japanese noun meaning “(unlikely event of) emergency, the worst(-case scenario), 10000 to 1, (if) by some chance”.
Meanings
- noun(unlikely event of) emergency; the worst(-case scenario); 10000 to 1
- adverb, adjectival noun(if) by some chance; by some possibility; in the unlikely event that
Examples
万一天気なら私は行きます。
Should it be fine, I will go.
万一失敗してもくじけるな。
Don't get discouraged if you should fail.
万一病気になったらどうする？
What would you do, if you should be taken ill?
Sentences from Tatoeba (CC BY 2.0 FR).