flabbergast

ot noun

1. Overwhelming confusion, shock, or surprise. His flabbergast was so great he couldn’t even come up with a plausible answer.
2. An awkward person.

fe’l verb

1. To overwhelm with bewilderment; to amaze, confound, or stun, especially in a ludicrous manner. He was flabbergasted to find that his work had been done for him before he began.