Singer Mars (5)
I believe the answer is:
bruno
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">singer mars</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for bruno that I've seen before include "Famous boxer" , "Sylvie and -- (Lewis Carroll)" , "Giordano -; Sylvie and -, Carroll" , "One of the 22 [FRANKS] who fought" .)