flabbergast UK /ˈflæbə(ˌ)ɡɑːst/US /ˈflæbɚˌɡæst/noun 2verb 1forms 3 noun2 •Overwhelming confusion, shock, or surprise.His flabbergast was so great he couldn’t even come up with a plausible answer. •An awkward person. verb1 •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.Her stupidity flabbergasts me, and I have to force myself to keep a straight face while she explains her beliefs. formsflabbergasted · flabbergasting · flabbergasts