Lacking in quantity or quality (6)
I believe the answer is:
meagre
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">lacking in quantity</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">quality</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I have seen 'Poor quality' mean 'meagre' so perhaps 'quality' could also mean 'meagre')</span><br/ ><br/ ></span>
(Other definitions for meagre that I've seen before include "Small, insufficient" , "Stingy - thin" , "skinny" , "Scarce - scanty" , "deficient in amount" .)