Co-founder of Rome (5)
I believe the answer is:
remus
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">co-founder of rome</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 remus that I've seen before include "Brother of 24 across" , "partner in City foundation" , "Co-founder of Rome" , "Suckled by a she-wolf, I was" , "Avuncular story-teller" .)