Cul-de-sac (4,3)
I believe the answer is:
dead end
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cul-de-sac</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dead end that I've seen before include "A blind alley, sounds moribund" , "Blind alley or situation without prospects" , "Impasse" , "Blind alley, cul-de-sac" , "that's leading nowhere" .)