Every religion has a form of meditation. If you are talking about Buddhist meditation, there are many different forms of that (over 50 in fact). Even in some forms of Mahayana and Theravada Buddhism there are devotional prayers/meditation to Buddha. Some forms, such as Zen, are more contemplative and work toward finding insight to one's own nature. Abrahamic meditation focuses on specific scriptures from their holy book in a similar way that Zen does when contemplating a Koan. Some devotional Tibetan Buddhism prays to a guru for wisdom. Mantras, Sutras, Scriptures...these are all very similar, and forms of meditation that involve focusing the mind on the meaning of these are similar. To directly answer your question. I believe prayer can put a person in a meditative state. I would say though that most prayers are not meditation, but some meditations are prayers.