professional

adjective

• 1relating to or belonging to a profession:young professional people
• worthy of or appropriate to a professional person; competent, skilful, or assured:his professional expertise their music is both memorable and professional

• 2engaged in a specified activity as one’s main paid occupation rather than as an amateur:a professional boxer
• informal, derogatory habitually making a feature of a particular activity or attribute:a professional gloom-monger

noun

• a person engaged or qualified in a profession:professionals such as lawyers and surveyors
• a person engaged in a specified activity, especially a sport, as a main paid occupation rather than as a pastime: his first season as a professional
• a person competent or skilled in a particular activity:she was a real professional on stage