Stern, or unpleasant (4)
I believe the answer is:
grim
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">stern</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that stern can be written as grim)</span><br/ ><br/ >'<span class="explanation-format__original">unpleasant</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ ></span>
(Other definitions for grim that I've seen before include "Dour, forbidding" , "Ghastly" , "Dour and severe" , "Harshly ironic" , "Frightful" .)