Accustomed to Jack leaving when offended (6)
I believe the answer is:
abused
'when offended' is the definition.
'abused' can be an answer for 'offended' (I've seen this before). I am unsure of the 'when' bit.
'accustomed to jack' is the wordplay.
'accustomed' becomes 'used' (I've seen this in other clues).
'to' says to put letters next to each other (I've seen this in other clues).
'jack' becomes 'ab' (both can mean a sailor).
'used' put after 'ab' is 'ABUSED'.
'leaving' is the link.
Can you help me to learn more?
(Other definitions for abused that I've seen before include "Reviled or exploited" , "Treated cruelly; insulted" , "were cruel to partners!" , "Took undue advantage of" , "Criminally maltreated" .)