Oddly overlooked artists unable to make ceremony (6)
I believe the answer is:
ritual
'ceremony' is the definition.
(I've seen this in other clues)
'oddly overlooked artists unable' is the wordplay.
'oddly overlooked' indicates alternate letters (letters in odd-numbered positions removed).
'artists'+'unable'='artistsunable'
The alternate letters of 'artistsunable' are 'RITUAL'.
'to make' is the link.
(Other definitions for ritual that I've seen before include "Ceremony, regular procedure" , "Habit, routine" , "Code of ceremonies" , "Custom, rite" , "Customary (eg religious) practice" .)