unbelievable, unreasonable, extraordinary, completely unexpected, outrageous, preposterous · not at all
köken: Many sources consider this to be a shift from 途でもない (to de mo nai, literally “that is not even the way”, idiomatically “extraordinary, unexpected, unreasonable”) or とでもない (to de mo nai, literally “that's not even [whatever came before]”, where the to here is the quotative particle to in reference to whatever was just said previously). However, citations for tondemonai precede those for todemonai…
come on, please, give me a break, stop messing around (an expression of disapproval or disapproving frustration, e.g. said to a person who is misbehaving) · come on, no way (an expression of disbelief, with the undertone of an accusation that the speaker is being lied to or being told a joke)
köken: Etymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Italic *n̥- Latin in- Latin crēdibilis Latin incrēdibilis From in- + crēdibilis.
Num mē fefellit, Catilīna, nōn modo rēs tanta, tam atrōx, tamque incrēdibilis, vērum — id quod multō magis est admīrandum — diēs?