Dictionary / Vocabulary / 半信半疑
はんしんはんぎ
half in doubt; half-convinced; dubious; incredulous
ああ、オレも実際、こうして目の当たりにするまでは半信半疑だったが・・・。
Yes, truthfully, until it was right in front of me like this, I half-doubted it ...
彼の言うことには半信半疑だ。
I don't quite believe what he says.