Superior points he passed on by mistake (8)
I believe the answer is:
snobbish
'superior' is the definition.
(thesaurus)
'points he passed on by mistake' is the wordplay.
'points' becomes 'sn'.
'he passed on' becomes 'ob' (abbreviation for obiit, Latin for 'died').
'by' means one lot of letters go next to another.
'mistake' becomes 'bish' (I've seen this in other clues).
'sn'+'ob'+'bish'='SNOBBISH'
(Other definitions for snobbish that I've seen before include "Given to overvaluing social status" , "Uppity, considering oneself socially superior" , "Considering oneself socially superior to others" , "stuck up" , "Condescending to inferiors" .)