Dumbfounded (6)
'dumbfounded' is the definition.
(synonyms)
This is all the clue.
(Other definitions for amazed that I've seen before include "Completely surprised" , "Astonished, stunned" , "Confounded" , "Greatly surprised or astonished" , "Awe-struck" .)
'dumbfounded' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for speechless that I've seen before include "Dumbstruck" , "being forced to improvise?" , "Struck dumb" , "Unable to say anything" , "Dumbfounded" .)