flabbergast

flabbergast — verb

1. to make someone feel extremely surprised and confused, often by giving them news

1.verbtransitiveC1
Definition

to make someone feel extremely surprised and confused, often by giving them news they had no idea was coming

Example

Leila felt completely flabbergasted when her best friend moved away without saying goodbye.

adjective pattern: feel + flabbergasted + when-clause

The mayor was flabbergasted by the news that the factory would close next month.

passive: be flabbergasted + by + noun phrase

Common collocations
  • flabbergasted by
  • flabbergasted at
  • absolutely flabbergasted
  • completely flabbergasted
  • leave someone flabbergasted
Synonyms
  • dumbfound

    similar level of shock, but slightly more formal and less common

  • astonish

    less extreme than flabbergast; used much more often in everyday conversation

  • stun

    can mean either mental or physical shock; broader in meaning

Grammar Patterns

flabbergast + object

be flabbergasted + by/at

be flabbergasted + to-infinitive

Usage Note

Almost always used in the passive voice (be flabbergasted) or as an adjective describing a person's reaction. The active form — subject + flabbergasts + object — is very rare in everyday speech.

Common Mistakes

I was very flabbergasted by the news.
I was flabbergasted by the news.
Flabbergasted already expresses a very high degree of surprise, so intensifiers like 'very' are redundant.

Word family

  • flabbergasted
    adjectiveC1
  • flabbergasting
    adjectiveC2

Synonym discussion

Sense: verb/1

All four words describe a strong reaction to something unexpected, but they differ in intensity and register. Astonished is the mildest and most common — it suggests genuine surprise without implying confusion or speechlessness. Stunned can describe either emotional shock or physical impact, making it slightly broader. Dumbfounded emphasizes being unable to speak or think clearly because of the surprise, just like flabbergasted, but sounds more formal or literary. Flabbergasted is the most vivid and informal of the group — it suggests a theatrical, almost comic level of shock, as if the person is left gaping. For a casual story about a surprising piece of news, flabbergasted fits best: 'I was flabbergasted when my neighbour said she was moving to New Zealand.' In a news report, astonished or stunned would be more appropriate: 'The team was stunned by the court's decision.'

astonished ↗dumbfoundedstunnedflabbergasted

Common collocations

Nouns

  • the news
  • the announcement
  • the discovery
  • the result

Adverbs

Phrases

  • leave someone flabbergasted
  • be flabbergasted to find
  • be flabbergasted to learn

Prepositions

Etymology

English (uncertain origin)

Flabbergast first appeared in English in the late 1700s, and no one knows exactly where it came from. Most language experts think it was made up as a playful combination of 'flabby' (or the sound 'flap') and 'aghast' (which means shocked with your mouth open). People probably created it to sound as funny and dramatic as the feeling itself — being so surprised that your body goes weak and you are left speechless.