Reverted (8)
(Other definitions for relapsed that I've seen before include "Sank back (into illness)" , "Deteriorated in health again" , "Failed to maintain improvement" , "Dropped back" , "Weakened" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">reverted</span>' is the definition.<br/ ><span class="explanation-format__explanation">('return' can be a synonym of 'revert')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for returned that I've seen before include "dishonoured by the bank" , "Honoured by the electorate" , "Sent back" , "Went, came or gave back" , "Went, came or brought back" .)