Oriental festival on the first of November (7)
I believe the answer is:
eastern
'oriental' is the definition.
(synonyms)
'festival on the first of november' is the wordplay.
'festival' becomes 'easter' (Christian festival).
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'the first of november' becomes 'n' (1st letter of 'november').
'easter'+'n'='EASTERN'
(Other definitions for eastern that I've seen before include "From Japan, say" , "Maybe Chinese" , "Coming from the Orient" , "Of the direction of the rising sun" , "Chinese', for example" .)