Definition - What does Yogi mean?
Yogi refers to a master practitioner of yoga. In classical Sanskrit literature, yogi specifically refers to male yoga disciples with the female connotation being yogini. Yogis are practitioners of asanas and pranayama (breath control). They are characterized by their enlightened attitude and their quality of Self-awareness.
Yogapedia explains Yogi
Yogi is the revered title bestowed upon individuals who live inspirational lives and are masters in the practice of yoga. In the Hindu tradition, yogis and yoginis are yoga disciples who have reached "the highest state of meditation," or samadhi.
Yogis are distinguished from others by the qualities present in their day-to-day lives. These qualities are referred to in the sacred Hindu text, the "Bhagavad Gita," or the "song of the blessed one," which is a dialogue between the human, Arjuna, and the god, Krishna. When Arjuna asks Krishna how he can achieve salvation, Krishna responds to him by prescribing the qualities found in a yogi. These qualities include a forgiving heart, a compassion for others and a devotion to the practice of yoga.