society > occupation and work > worker > [adjective] > trained in theoretic part of occupation > following occupation as livelihood (6)
Of a person or persons: that engages in a specified occupation or activity for money or as a means of earning a living, rather than as a pastime…
Of or relating to a profession; (also) that is such by profession, professional.
Of a person: engaging in an activity, esp. a sport, on a professional rather than an amateur basis; (of an activity, esp. a sporting competition)…