S: (n) master, professional (an authority qualified to teach apprentices)
Adjective
S: (adj) professional (engaged in a profession or engaging in as a profession or means of livelihood) "the professional man or woman possesses distinctive qualifications"; "began her professional career after the Olympics"; "professional theater"; "professional football"; "a professional cook"; "professional actors and athletes"
S: (adj) professional (of or relating to or suitable as a profession) "professional organizations"; "a professional field such as law"
S: (adj) professional (characteristic of or befitting a profession or one engaged in a profession) "professional conduct"; "professional ethics"; "a thoroughly professional performance"
S: (adj) professional (of or relating to a profession) "we need professional advice"; "professional training"; "professional equipment for his new office"
S: (adj) professional (engaged in by members of a profession) "professional occupations include medicine and the law and teaching"