Welsh valley (3)
I believe the answer is:
cwm
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">welsh valley</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for cwm that I've seen before include "Bronwen's depression" , "Welsh mountainside hollow" , "Steep Welsh hollow" , "Valley (in Wales)" , "Welsh valley hollow" .)