Drearily dull (4)
I believe the answer is:
drab
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">drearily dull</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for drab that I've seen before include "Cheerless, shabby" , "Tedious" , "Dreary and colourless" , "Dull and boring" , "Not cheering" .)