Oriental festival's name (7)
I believe the answer is:
eastern
'oriental' is the definition.
('eastern' can be a synonym of 'oriental')
'festival's name' is the wordplay.
'festival' becomes 'easter' (I've seen this before).
'name' becomes 'n' (common abbreviation e.g. on forms).
'easter'+'n'='EASTERN'
(Other definitions for eastern that I've seen before include "From Japan, say" , "Coming from the Orient" , "See 11" , "Indian perhaps" , "towards daybreak?" .)