a.
n. A person who prosecutes anything professionally, or for a livelihood, and not in the character of an amateur; a professional worker. [ 1913 Webster ]
n. The following of a profession, sport, etc., as an occupation; -- opposed to
n. professional person. [ R. ] [ 1913 Webster ]
adv. In a professional manner or capacity; by profession or calling; in the exercise of one's profession; one employed professionally. [ 1913 Webster ]