flabbergast
1 synonym for flabbergast, grouped by meaning and by how common each one is.
Verb — To shock someone so much that they are left speechless, often in a comical way.
Synonyms
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
Etymology
The verb's origin is uncertain; it may be dialectal (Suffolk), formed from flabby or flap ("to strike") and aghast. It might also be related to Scottish flabrigast ("to boast") or flabrigastit ("worn out with exertion"). The noun comes from the verb.
Full origin of flabbergast →