Shortage, paucity (6)
I believe the answer is:
dearth
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">shortage</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(dearth can mean a shortage or lack)</span><br/ ><br/ >'<span class="explanation-format__original">paucity</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for dearth that I've seen before include "Acute insufficiency" , "In short supply" , "poverty" , "Shortage, lack" , "Acute shortage" .)