Five hundred in gleaming row (6)
I believe the answer is:
shindy
'row' is the definition.
(thesaurus)
'five hundred in gleaming' is the wordplay.
'five hundred' becomes 'D' (Roman numeral for 500).
'in' is an insertion indicator.
'gleaming' becomes 'shiny' (I've seen this before).
'd' inserted into 'shiny' is 'SHINDY'.
(Other definitions for shindy that I've seen before include "Large lively party" , "noisy party" , "Disturbance" , "disorderly party" , "quarrel" .)