Synonyms/Hypernyms (Ordered by Estimated Frequency) of verb flabbergast

1 sense of flabbergast

Sense 1
flabbergast, boggle, bowl over -- (overcome with amazement; "This boggles the mind!")
       => surprise -- (cause to be surprised; "The news really surprised me")

Antonyms of adj flabbergasted

1 sense of flabbergasted

Sense 1
dumbfounded, dumfounded, flabbergasted, stupefied, thunderstruck, dumbstruck, dumbstricken -- (as if struck dumb with astonishment and surprise; "a circle of policement stood dumbfounded by her denial of having seen the accident"; "the flabbergasted aldermen were speechless"; "was thunderstruck by the news of his promotion")

INDIRECT (VIA surprised) -> unsurprised, not surprised -- (not surprised or expressing surprise; "that unsuprised obstinate look on his face")

Similarity of adj flabbergasted

1 sense of flabbergasted

Sense 1
dumbfounded, dumfounded, flabbergasted, stupefied, thunderstruck, dumbstruck, dumbstricken -- (as if struck dumb with astonishment and surprise; "a circle of policement stood dumbfounded by her denial of having seen the accident"; "the flabbergasted aldermen were speechless"; "was thunderstruck by the news of his promotion")
       => surprised (vs. unsurprised) -- (taken unawares or suddenly and feeling wonder or astonishment; "surprised by her student's ingenuity"; "surprised that he remembered my name"; "a surprised expression")