Queen of the Nile, informally (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">queen of the nile informally</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for cleo that I've seen before include "Jazz singer, ___ Laine" , "She ruled" , "Ms Laine - one of the 14 films" , "Woman" , "Dame Laine" .)