Insulted (8)
(Other definitions for offended that I've seen before include "Upset" , "Hurt the feelins of" , "Annoyed because of a perceived insult" , "Committed an illegal act" , "Caused to feel hurt" .)
'insulted' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for slighted that I've seen before include "Insulted with delights" , "Gave the cold shoulder to" , "Offended" , "put down" .)