Certain lap dog, informally (3)
I believe the answer is:
pom
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">certain lap dog informally</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 pom that I've seen before include "Pomeranian dog" , "Brit abroad" , "Australian term for Englishman" , "Little dog" , "Limey in Oz" .)