疑ぎ団だん

noun

deep-seated doubt; unresolvable doubt

Refers to a lingering, often fundamental doubt that cannot be easily dispelled. Literary and somewhat formal.

• 彼かれの説せつ明めいを聞きいても、心こころの奥おくに疑ぎ団だんが残のこった。

  Even after hearing his explanation, a deep-seated doubt remained in my heart.