Run a metro badly, producing fractional dividend (9)
I believe the answer is:
numerator
'fractional dividend' is the definition.
(I've seen this before)
'run a metro badly' is the wordplay.
'badly' is an anagram indicator (letters in the wrong order).
'run'+'a'+'metro'='runametro'
'runametro' with letters rearranged gives 'NUMERATOR'.
'producing' acts as a link.
(Other definitions for numerator that I've seen before include "Figure going over a line" , "the superior figure" , "One counts" , "Upper half of fraction" , "Top half of 1/2 , for example" .)