What does flabbergast mean?
To flabbergast someone is to overwhelm them with astonishment so complete that they are momentarily left speechless or bewildered. The word is almost always used transitively — a piece of news, an unexpected result, or an audacious act flabbergasts a person — though in everyday conversation it appears far more often through its participle form, 'flabbergasted', which describes the stunned state itself. Informal in register and strongly associated with comic exaggeration, flabbergast signals a level of surprise well beyond mere astonishment: it suggests being knocked off balance by the sheer unexpectedness of something. Despite its long presence in English, the word's origin remains genuinely mysterious; it first surfaced in the late eighteenth century with no clearly documented ancestry, and one widely repeated theory holds that it was invented as a playful blend of 'flabby' and 'aghast' or 'gast' (to frighten). Whatever its true pedigree, its expressive power is undisputed — few words convey dumbfounded amazement as vividly or memorably.
verb (also used as an adjective in the form 'flabbergasted')To overwhelm someone with utter astonishment, leaving them speechless or bewildered.
- To astound or bewilder someone so completely that they are left speechless; to overwhelm with surprise.
"The jury's verdict utterly flabbergasted even the most seasoned reporters in the courtroom."
"The announcement that the small town had won the national award flabbergasted residents and officials alike."
"She was utterly flabbergasted when her quiet colleague stood up and delivered a flawless impromptu speech."
Nobody knows for sure where 'flabbergast' came from — it appeared out of nowhere in the late 18th century, possibly as a joke combining 'flabby' and 'ghast', and has been astonishing people ever since.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of flabbergast
The origin of 'flabbergast' is famously obscure. It first appears in English in the latter half of the eighteenth century, with no documented ancestry in Latin, Greek, or any other language, leading many scholars to suspect it may have been deliberately coined — possibly as a humorous blend of 'flabby' (or 'flap') and elements of 'aghast' or 'gast', an old sense of terrifying someone into stunned silence. If so, it would be a rare example of a successful invented compound entering common usage. Its only close relative is its own derivative 'flabbergasted'; there are no established cognates in other languages.
Related word forms
How flabbergast is actually used
'Flabbergast' is informal to mildly formal-neutral in tone and carries an almost always positive or comic connotation of comic exaggeration — it implies astonishment beyond ordinary surprise. It is typically used transitively ('the news flabbergasted us') and appears more often through its participle form 'flabbergasted'. It is common throughout the English-speaking world, with no meaningful regional restriction.
Easily confused with flabbergast
'Aghast' describes being struck with shock or horror at something frightening or dreadful, whereas 'flabbergast' conveys overwhelming astonishment at something surprising rather than horrifying.
'Flabbergast' is the verb describing the act of astonishing someone, while 'flabbergasted' is the resulting adjective/participle describing the person's state of astonishment.