In Hindu usage, personal realization of that inward soul called atman which is a portion of the universal essence or Brahman. Hence a realization of man's oneness with the universe and a realization of his deity.
In Buddhism, a merging of the personal Buddha energy with the universal Buddha nature or universal energy.
Pat Means, The Mystical Means, Campus Crusade for Christ, 1976. p. 200
The revelation of Absolute Truth
Buddhism, Taoism, & Other Far Eastern Religions J. Isamu Yamamoto, Zondervan, Grand Rapids, MI, 1998. p.94