Relax, loosen (4)
I believe the answer is:
ease
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">relax</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(eg to ease a restriction is to relax it)</span><br/ ><br/ >'<span class="explanation-format__original">loosen</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for ease that I've seen before include "Allay" , "Poise or leisure" , "Relief" , "No trouble" , "Freedom from worries" .)