Put emphasis on (6)
I believe the answer is:
stress
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">put emphasis on</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 stress that I've seen before include "Emphasis on anxiety?" , "Lay emphasis on - it's a strain" , "what causes tension" , "Highlight" , "Strain or accentuate" .)