Speechless
Pronunciation : Speech"less
Part of Speech : a.
Definition : 1. Destitute or deprived of the faculty of speech.
2. Not speaking for a time; dumb; mute; silent. Speechless with wonder, and half dead with fear. Addison. -- Speech"less*ly, adv. -- Speech"less*ness, n.
Source : Webster's Unabridged Dictionary, 1913