Polite noun for prayer, often used in religious contexts or when asking for divine help.
I say a prayer at the family altar every morning.
I say a prayer every night before bed.
She prayed for success on the exam.
I prayed for her recovery.
We offered a prayer at the shrine.
祈り is the plain, direct noun for a prayer, while お祈り adds a polite お- prefix used in everyday and religious speech.
rejection email; job application rejection notice
Polite prefix お + noun 祈り (prayer), from verb 祈る (to pray).