Meaning

• An awkward person.

• Overwhelming confusion, shock, or surprise.

  "His flabbergast was so great he couldn’t even come up with a plausible answer."

Meaning

• 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."