ichidan verb, intransitive verb
be flabbergasted; be dumbfounded
Expresses extreme astonishment or disbelief, often at someone's outrageous behavior or an unbelievable situation. Stronger than 呆れる alone.
彼の無責任な態度には呆れ果てた。
I was utterly dumbfounded by his irresponsible attitude.
あまり
I was so flabbergasted by the outrageous lie that I was speechless.