"Yoga [is] a systematic discipline which includes a technique for the mastery of the bodily organism and for rendering it healthy....and various methods or techniques of mind training for the sake of gaining the final knowledge and liberation. According to the Hindu religious tradition it was revealed to [humanity] by [The Lord] and even gods gained immortality and their supreme powers by its practice."
Werner, Karel. A Popular Dictionary of Hinduism, p. 182
"The term Yoga comes from the root yuj, "to yoke or join." Here it is used to mean the Union of the individual spirit...with the Universal Spirit...The art of Yoga is defined as a system of culture for perfecting human efficiency. It claims to destroy the defects and diseases of the body and mind, to establish health and bestow happiness, to develop intelligence, and reveal true knowledge of Self, and to extract the nectar of all things."
Bernard, Theos. Hindu Philosophy, p. 86