Smithy; counterfeit (5)
I believe the answer is:
forge
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">smithy</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">counterfeit</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that counterfeit can be written as forge)</span><br/ ><br/ ></span>
(Other definitions for forge that I've seen before include "Counterfeit - smithy" , "Create; counterfeit" , "Ironworks" , "Blacksmith's premises" , "Smith's workshop" .)