Jewish festival (8)
(Other definitions for passover that I've seen before include "Disregard - Jewish festival" , "spring festival" , "religious festival" , "feast - with 25a" .)
'jewish festival' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for purim that I've seen before include "Jewish feast" , "Jewish festival" , "Jewish holy day" .)