lost for words

unable to think of something to say at a loss for words Chris was lost for words at Kathy's incredible rudeness.

Usage notes: usually said because something has surprised you

Name	Pronounced	Usage
Camellia	kə-MEEL-ee-ə, kə-MEL-ee-ə	English (Rare)
Asturias	[ə'stuəri:əs]
Peg	[peg]
Eoin	O-in	Irish, Scottish
Emmanuel	e-man-WEL (French), i-MAN-yə-wəl (English), i-MAN-yəl (English)	Biblical, French, English
Ansell	['ænsəl]