Speechless (4,3,5)
'speechless' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for dumb that I've seen before include "Mute" , "Voiceless" , "Silent" , "Ignorant (US colloq.); speechless" , "Incapable of speech" .)
'speechless' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for mute that I've seen before include "Deaden sound of" , "Device that softens the tone of a musical instrument" , "Silent or speechless" , "Unspeaking" , "Violin clamp; type of swan" .)
'speechless' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mum that I've seen before include "Parent (who's kept or is the word!)" , "Quiet; relative" , "Keep it secret from mother?" , "Informal palindromic mother" , "Tight-lipped" .)
'speechless' is the definition.
(I've seen this before)
This is all the clue.
(Another definition for lost for words that I've seen is " Speechless - like stumped solver?".)