Inconsistent, sporadic (6)
I believe the answer is:
patchy
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">inconsistent</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">sporadic</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for patchy that I've seen before include "Irregular in quality" , "Morose" , "Inconsistent" , "Uneven in quality; showing signs of repair" , "Intermittent" .)