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

1.
quedarse sin palabras, no tener palabras
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.
Cuando vio la fiesta sorpresa, se quedó completamente sin palabras.
•
His rude comment left me lost for words.
Su comentario grosero me dejó sin palabras.