Northern Irish county; in low spirits (4)
I believe the answer is:
down
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">northern irish county</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(County Down in Northern Ireland)</span><br/ ><br/ >'<span class="explanation-format__original">in low spirits</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ ></span>
(Other definitions for down that I've seen before include "like the other set of clues" , "See 18" , "Not working (computer)" , "Depressed; swallow" , "In a low mood; hill" .)