South Wales town (5)
I believe the answer is:
neath
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">south wales town</span>' is the definition.<br/ ><span class="explanation-format__explanation">(Welsh town)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for neath that I've seen before include "town in South Wales" , "not on top" , "River" , "Lower than - a town in West Glamorgan" , "Welsh rugby club" .)