Speechless (4,3,5)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">speechless</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dumb that I've seen before include "Mute" , "Voiceless" , "Silent" , "Ignorant (US colloq.); speechless" , "Incapable of speech" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">speechless</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(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" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">speechless</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(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" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">speechless</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Another definition for lost for words that I've seen is " Speechless - like stumped solver?".)