Lake or pond (4)
I believe the answer is:
mere
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">lake</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(mere is a kind of lake)</span><br/ ><br/ >'<span class="explanation-format__original">pond</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(mere is a kind of pond)</span><br/ ><br/ ></span>
(Other definitions for mere that I've seen before include "DDwater" , "Nothing more than a small pool" , "Lake in Cumbria" , "Pond, only what is said" , "Just an English lake" .)