Bart Simpson's bus driver (4)
I believe the answer is:
otto
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bart simpson's bus driver</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 otto that I've seen before include "Palindromic German name like Bismark's" , "Cooker" , "that smells quite nice" , "Rose oil; man's name" , "Something oily" .)