Praxis, a transliteration of the Greek word πρᾶξις (derived from the stem of the verb πράσσειν, prassein "to do, to act"), means "practice, action, doing". More particularly, it means either: 1. * practice, as distinguished from theory, of an art, science, etc.; or practical application or exercise of a branch of learning; 2. * habitual or established practice; custom.