Decomposes (4)
I believe the answer is:
rots
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">decomposes</span>' is the definition.<br/ ><span class="explanation-format__explanation">('rot' can be a synonym of 'decompose')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for rots that I've seen before include "Decays" , "Decomposes" .)