Abhyāsa, in Hinduism, is a spiritual practice which is regularly and constantly practised over a long period of time.
It has been prescribed by the great sage Patanjali in his Yoga Sutras, and by Krishna in the Bhagavad Gita as an essential means to control the mind, together with Vairāgya.
[1][2] Sutra 1:12 "Both practice (abhyāsa) and non-reaction (vairāgya) are required to still the patterning of consciousness.
"—as translated by Chip Hartranft in his work The Yoga Sutra of Patanjali.
[3] According to Swami Krishnananda sutra 1:13 means "Abhyasa or practice is the effort to fix one's own self in a given attitude."