adverb
(not) possibly; by no means; utterly
Always used with a negative predicate (ない, できない, 無理, etc.) to express strong impossibility or denial. Emphasizes that something is completely out of the question.
この問題は難しすぎて、とうてい解けない。
This problem is too difficult; I can't possibly solve it.
彼の提案は、とうてい受け入れられない。
His proposal is utterly unacceptable.