Wimbledon unit (3)
I believe the answer is:
set
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wimbledon unit</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 set that I've seen before include "Become fixed or solid" , "Solidify; group" , "Become stiff like jelly" , "Fix; lay" , "Cake < , plonk < , something served" .)