Melts (5)
I believe the answer is:
thaws
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">melts</span>' is the definition.<br/ ><span class="explanation-format__explanation">('thaw' can be a synonym of 'melt')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for thaws that I've seen before include "(Of snow) melts" , "friendlier times?" , "As role of Morse was to become" , "Starts to unfreeze" .)