flabbergast
UK[ˈflæbəɡɑːst]US[ˈflæbərɡæst]
v
To overwhelm with shock, surprise, or wonder
Etymology
The origin of 'flabbergast' is obscure but delightfully expressive. It first appeared in the late 1700s, potentially as a playful combination of 'flabby' or 'flap' and 'aghast' or 'gast' (an archaic word meaning to terrify). The word's formation seems driven by a desire for a vigorous, somewhat humorous term to describe a state of stunned astonishment. Its whimsical sound pattern likely contributed to its survival and adoption into standard English, where it now serves as a vivid, if informal, synonym for amazement.
Analysis
This word is considered an unsegmentable simplex. It is likely a fanciful 18th-century coinage, possibly a blend of other words, with no clear, separable morphemes in the modern sense.
Examples
The magician's final trick completely flabbergasted the audience.
I was utterly flabbergasted to hear the unexpected news.
His audacious proposal left the committee members flabbergasted.