What does とんでもない mean?
とんでもない is a Japanese adjective meaning “outrageous, No way!” in English. It can also be translated as “absolutely not!, (it was) no bother at all” depending on context. It is written as とんでもない in hiragana, and tondemonai in romaji. This word is part of JLPT N3 vocabulary.
Example sentences
ジャックが音楽が苦手なんてとんでもない、それどころか、ピアノを弾くのがうまい。
It isn't true that Jack is no good at music, on the contrary, he plays the piano well.
「君はそれを終えたか」「とんでもない、始めたばかりだ」
"Have you finished it?" "On the contrary, I've just begun."