Sell Tate off causing feud (8)
I believe the answer is:
vendetta
'feud' is the definition.
(vendetta is a kind of feud)
'sell tate off' is the wordplay.
'sell' becomes 'vend' (vending is a kind of selling).
'off' indicates anagramming the letters.
'tate' anagrammed gives 'etta'.
'vend'+'etta'='VENDETTA'
'causing' acts as a link.
(Other definitions for vendetta that I've seen before include "Bitter feud between families" , "Violent feud" , "Murderous feud" , "intense feud" , "murderous campaign?" .)