万が一

adverbまんがいち · mangaichi

1. English(if) by some chance; by some possibility; in the unlikely event that; 10000 to 1

   • 万が一気が変わったら、知らせて下さい。If you change your mind, let me know.

2. English(unlikely event of) emergency; the worst(-case scenario)

   • 万が一に備えて、武器になるものを探した。I looked around for a weapon just in case.

Source: JMdict (EDRDG) · CC BY-SA 4.0 (EDRDG)