someone's jaw drops (open)

US /ˈsʌm.wʌnz dʒɔː drɑps (ˈoʊ.pən)/
UK /ˈsʌm.wʌnz dʒɔː drɑps (ˈoʊ.pən)/
"someone's jaw drops (open)" picture
1.

mond openvallen, verbaasd zijn

used to say that someone looks very surprised or shocked

:
When she announced her engagement, everyone's jaw dropped.
Toen ze haar verloving aankondigde, viel ieders mond open.
My jaw dropped open when I saw the price of the new car.
Mijn mond viel open toen ik de prijs van de nieuwe auto zag.