Tacit assent (3)
I believe the answer is:
nod
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tacit assent</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for nod that I've seen before include "positive sign" , "Where Cain went to" , "Indicate assent with head movement" , "Show recognition" , "What Homer may sometime do" .)