Time to argue for disloyalty (7)
I believe the answer is:
treason
'disloyalty' is the definition.
(treason is a kind of disloyalty)
'time to argue' is the wordplay.
'time' becomes 't'.
'to argue' becomes 'reason' ('reason' can be a synonym of 'argue').
't'+'reason'='TREASON'
'for' acts as a link.
(Other definitions for treason that I've seen before include "Betrayal of the state" , "Gunpowder Plot, say" , "One rats (anag)" , "Lese-majesty" , "rebellion" .)