RichThesaurus
leave someone open-mouthed
vs
take aback
leave someone open-mouthed
take aback
verb
To surprise or shock; to discomfit.
Of a ship: to catch it with the sails aback suddenly.
How often have the words
leave someone open-mouthed
and
take aback
occurred in a corpus of books?
(source:
Google Ngram Viewer
)