A person who belongs to a profession.
A person who earns their living from a specified activity.
(euphemistic) A prostitute.
An expert.
One of four categories of sociologist propounded by Horowitz: a sociologist who is actively concerned with promoting the profession of sociology.
Of, pertaining to, or in accordance with the (usually high) standards of a profession.
That is carried out for money, especially as a livelihood.
(by extension) Expert.