Definition of Yogi:
Lameness: He does not run after the illusions of the world.
Blindness: He is blind to the sights and distractions of the world.
Deafness: He is deaf to the cacophony of the world.
Impotence: He imposed on himself abstinence.
Dullness: He is not interesting in any way.
The Yogi, the knower of Brahman knowledge, chose to be lame not running after the illusions of the world, blind not seeing the sights and distractions of the world; deaf not hearing the din of the world; impotent, not acting, and eschewing grihastya (life of householder); and dull, completely unmindful of the world.