Intensely cold (6)
I believe the answer is:
bitter
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">intensely cold</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for bitter that I've seen before include "Hard to accept" , "Dry ale in the UK" , "Sour kind of English ale?" , "English beer, sounds sour" , "Kind of British beer" .)