mid-15c., profeshinalle, in reference to the profession of religious orders; see profession. By 1747 of careers, "pertaining to or appropriate to a profession or calling" (especially of the skilled or learned trades from c. 1793); In sports and amusements, "undertaken or engaged in for money" (opposed to amateur), by 1846. Related: Professionally.
"a professional person, one who follows a trade or occupation in a professional way," 1798, from professional (adj.).