The Sanskrit word Yoga means yoke or union: the alignment and process toward union with the Cosmic Spirit.
Within the International Nath Order that is the whole of the word. It is not a system of stretches. Meditation is how the sitting is done. Tantra is the pagan science that works toward the same union. Twilight Yoga is Mahendranath’s name for his teaching expressed as a yoga. Awakening is the experiential aim. None of these is a grade conferred by initiation. The householder Nath practices. The asana industry is another subject.