At a loss for words (4)
(Other definitions for awed that I've seen before include "Cowed" , "shock" , "Filled with respect (or dread)" , "was dazzling" , "Wade (anag.)" .)
(Another definition for dumbfounded that I've seen is " Gobsmacked".)
'at a loss for words' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tongue-tied that I've seen before include "Speechless from embarrassment" , "Unable to say" , "Unable to speak coherently" , "(Out of shyness) barely able to speak" , "Speechless with shyness" .)