PYS Sutra 1.1 Definition of Yoga

योगश्चित्तवृत्तिनिरोधः ॥१.२॥

Yogaścittavṛttinirodhaḥ ||1.2||

yógaḥ           Yoga

nirodhaḥ        is the suppression

vṛtti              of the modifications

citta             of the mind-stuff

yoga     = Concentration or to be absorbed in an idea (description of the same will follow later.)

citta      = mind-stuff – the subtlest of the finest form of matter (Prakriti) in humans which is illuminated by the Absolute Consciousness (Purusha)

vṛtti       = activities, fluctuations, modifications, changes of the mind-stuff, waves of thought forming in the mind like whirlpools in a lake

nirodhaḥ = control, channelling, mastery, quieting of vrittis