A jīvanmukta, literally meaning 'liberated while living', is a person who, in the Vedānta philosophy, has gained complete self-knowledge and self-realisation and attained kaivalya or moksha (enlightenment and liberation), thus is liberated while living and not yet died. The state is the aim of moksha in Vedānta, Yoga and other schools of Hinduism, and it is referred to as jīvanmukti (Liberation or Enlightenment).
Jīvanmuktas are also called ātma-jnāni (self-realized) because they are knowers of their true self (ātman) and the universal self, hence also called Brahma-jñāni. At the end of their lives, jīvanmuktas destroy remaining karmas and attain parāmukti (final liberation) and become parāmukta. When a jīvanmukta gives his insight to others and teaches them about his / her realisation of the true nature of the ultimate reality (Brahman) and self (Atman), taking the role of a guru to show the path of Moksha to others, then that jīvanmukta is called an avadhūta. Some avadhūtas also achieve the title of Paramahamsa. When a rishi (seer / sage) becomes a jīvanmukta then that rishi is called Brahmarshi.
Some examples of jivanmuktas are Mahāvīra, Buddha, Adi Śhankarāchārya, Saint Dnyāneshwar, Kabīrdās, Śrī Chaitanya Mahāprabhu, Rāmakrishna Paramahansa, Ramana Maharshi, Shirdi Sai Baba, Vishwāmitra, Vedānta Deśika, Swāminārāyan, and Swami Ramdas. They realized Self (atman) i.e. God within their lifetime by traveling the path of pure Spirituality. They reached the stage of Enlightenment, Self-Realization, God-Realization, jivanmukti, Atma-jnana (all words are synonyms). They have negated the karma to zero, to reach the state of Jīvan-Mukti. After gaining enlightenment, they retained their body, to disseminate the Jnāna to masses. After leaving the body, they attained Paramukti.
Jīvanmukta (जीवन्मुक्त) is an adjective derived from a combination of Sanskrit noun जीव jīva, "life", and the past participle of the verb मुच् (much, or IAST muc), "to liberate". Monier-Williams gives the meaning "emancipated while still alive".