Antonyms of adj thunderstruck
1 sense of thunderstruck
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 thunderstruck
1 sense of thunderstruck
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")