The capability to perform the duties of one's profession generally, or to perform a particular professional task, with skill of an acceptable quality.
The capability to perform acceptably those duties directly related to patient care.
The ability of bacterial cells to take up exogenous DNA and be genetically transformed by it.
The expected function of a member of a particular profession.
Men and women working in the provision of health services, whether as individual practitioners or employees of health institutions and programs, whether or not professionally trained, and whether or not subject to public regulation. (From A Discursive Dictionary of Health Care, 1976)