Definition - What does Vaishnava mean?
Vaishnava is a term that describes a member of the largest denomination of Hinduism, Vaishnavism. Vaishnavas may also be called Vaishnavites. There are many subdivisions of Vaishnavism, so Vaishnavas may hold different beliefs and worship in different ways, but they all worship the god, Vishnu, or one of his incarnations, as the supreme deity. The most common Vishnu avatars worshiped as the supreme god are Krishna and Rama.
Vaishnava is also used as an adjective, as in “Vaishnava literature” or “Vaishnava temples.”
Yogapedia explains Vaishnava
The Vaishnavas' main religious text is the Bhagavad Gita in which Krishna is the main character. Vaishnavas believe in the concept of bhakti (devotion) and the practice of Bhakti yoga, which is the path to spiritual liberation based on devotion to the supreme god.
Estimates of the number of Vaishnavas vary from 200 million to 641 million, or more than 67 percent of Hindus, most of whom live in India, particularly in the western states. Although the number of Vaishnavas outside of India is small, the Gaudiya Vaishnava branch has seen an increase in members through the efforts of the International Society for Krishna Consciousness.