まんいち(~万一)manichi (manichi)
Meaning: just in case; by some possibility
Explain:
Often used with bad meanings
Example sentences:
1, 万一あの夫婦は離婚したら子供たちに大変です。
Manichi ano fūfu wa rikon shitara kodomo-tachi ni taihendesu.
If the couple in case of divorce, it will be difficult for the children
2, 万一彼は仕事を辞めたら皆さんは寂しくなれるです。
Manichi kare wa shigoto o yametara minasan wa sabishiku narerudesu.
Should he quit his job, everyone can be lonely.
3, まんいち病気になったら困るので旅行保険に入った。
Manichi byōki ni nattara komarunode ryokō hoken ni haitta.
Just in case for sick, I bought a travel insurance