1
unthinkable;unexpected;outrageous;offensive
See also:
とんでも無い (とんでもない)
1
adjective (keiyoushi)
unthinkable;unexpected;absurd;outrageous;preposterous;terrible
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.
2
interjection (kandoushi)
absolutely not!;far from it!;impossible!;preposterous!;what a thing to say!;no way!
「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."
3
interjection (kandoushi)
(it was) no bother at all;not at all;don't mention it
Other forms
飛んでもない 【とんでもない】 (search-only kanji form)