Canonical definition
A nāma mantra invokes a deity by name, typically in the form "Oṃ Namaḥ [Deity]āya" or "Oṃ Namo [Deity]āya" — grammatically a salutation. These are the mantras most central to Bhakti practice, since repeating a deity's name (japa) is itself considered a complete spiritual path in several devotional traditions. This category includes mantras such as Oṃ Namaḥ Śivāya (the Pañcākṣarī), Oṃ Namo Nārāyaṇāya (the Aṣṭākṣarī), and the Hare Kṛṣṇa Mahāmantra.