Duke, one with ability to see discord (8)
I believe the answer is:
division
'discord' is the definition.
(division is a kind of discord)
'duke one with ability' is the wordplay.
'duke' becomes 'd'.
'one with' becomes 'i' (I've seen this in other clues).
'ability' becomes 'vision' (vision is a kind of ability**).
'd'+'i'+'vision'='DIVISION'
'to see' acts as a link.
(Other definitions for division that I've seen before include "Part of a whole, a section" , "Section of organisation" , "Section; maths process" , "between a regiment and a corps?" , "The inverse of multiplication" .)