be lost for words
US /bi lɔst fɔr wɜrdz/
UK /bi lɔst fɔr wɜrdz/

1.
essere senza parole, rimanere a bocca aperta
to be so surprised, confused, or emotional that you cannot think of anything to say
:
•
When she saw the surprise party, she was completely lost for words.
Quando vide la festa a sorpresa, rimase completamente senza parole.
•
His rude comment left me lost for words.
Il suo commento scortese mi ha lasciato senza parole.