U2 singer (4)
I believe the answer is:
bono
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">u2 singer</span>' is the definition.<br/ ><span class="explanation-format__explanation">(Bono is the frontman of U2)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for bono that I've seen before include "U2 frontman" , "U2's main singer and lyricist" , "Pro . . . . publico - for the common good" , "Lead singer of U2" , "U2's star vocalist" .)