Long to get up for Muslim festival (3)
I believe the answer is:
eid
'muslim festival' is the definition.
(Islamic term for festival, eg Eid al-Fitr)
'long to get up' is the wordplay.
'long' becomes 'die' (to long for or to die for something is to crave it).
'to get up' is a reversal indicator.
'die' in reverse letter order is 'EID'.
'for' acts as a link.
(Other definitions for eid that I've seen before include "religious festival" , "feast" .)