Adopted son of Claudius (4)
I believe the answer is:
nero
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">adopted son of claudius</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 nero that I've seen before include "Roman arsonist and fiddler" , "Emperor (who fiddled while Rome burned?) d. AD68" , "Roman Emperor, 54-68 AD" , "Matricidal emperor" , "Fiddling Roman emperor" .)