Dallas family name (5)
I believe the answer is:
ewing
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dallas family name</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 ewing that I've seen before include "Fictional oil baron" , "Oil family" .)