Alienate (8)
I believe the answer is:
estrange
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">alienate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that alienate can be written as estrange)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for estrange that I've seen before include "Anger set (anag.)" , "As Regent (anag.)" , "Lose friendship" , "Reagents (anag.)" , "disunity" .)