Sole; merely (4)
I believe the answer is:
only
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">sole</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that sole can be written as only)</span><br/ ><br/ >'<span class="explanation-format__original">merely</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that merely can be written as only)</span><br/ ><br/ ></span>
(Other definitions for only that I've seen before include "And nothing more; sole" , "Unique; merely" , "And no one else" , "Existing alone with no other, perhaps a child" , "Alone; solitary" .)