Spoke indistinctly in a low voice (8)
I believe the answer is:
muttered
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">spoke indistinctly in a low voice</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>
(Other definitions for muttered that I've seen before include "Spoke indistinctly in a low voice" , "Spoke in low unclear voice, uttered subdued grumble" , "Talked in a barely audible voice" , "Talked indistinctly in a low voice" , "Murmured, mumbled" .)