Devise, cook up (7)
I believe the answer is:
concoct
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">devise</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">cook up</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for concoct that I've seen before include "Invent, devise" , "Fabricate" , "cook" , "Invent (a story/plan)" , "Invent (a story)" .)