Catches fire (7)
I believe the answer is:
ignites
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">catches fire</span>' is the definition.<br/ ><span class="explanation-format__explanation">('ignite' can be a synonym of 'catch fire')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ignites that I've seen before include "Sets on fire" , "Catches fire" , "Sets alight" , "lights" .)