Definition - What does Agni mean?
Agni is a Sanskrit word that means “fire” and refers to a Hindu deity of the same name. Agni, the god of fire, sacrifice and divine knowledge, is one of the primary Vedic gods and is considered second only to Indra, the king of the gods. Agni represents the spark of life and energy within all people. As that spark, Agni is present in all living things.
Agni also represents the divine knowledge that guides yogis toward the gods. He is the fire of the sun and lightning and the one who conveys sacrifices to the gods. Agni is also the lord protector of home and hearth, and as such, is a mediator between gods and people. Today, he is still worshiped - his blessings sought at marriages, deaths and other occasions.
Yogapedia explains Agni
In the ancient practice of Ayurveda medicine, agni is considered a form of energy. It is the biological fire that controls metabolism, digestion and the immune system. By balancing the agni energy and digestive system through Ayurveda, the individual enjoys better health, reduced stress and a calm mind.
There is also a yoga practice dedicated to agni. Agni yoga was founded in 1920 by Nicolas and Helena Roerich to emphasize living an ethical life, bringing spiritual consciousness into the moment. The practice of Agni yoga does not involve asanas, mantras, meditation or a teacher/master. It emphasizes individual striving to live a moral life free from prejudices and dogmas of the past. Agni yoga encourages discovering spiritual and moral guideposts and an inner fiery energy to help govern life and promote the common good.