1. 1. Of, relating to, engaged in, or suitable for a profession: lawyers, doctors, and other professional people.
   2. Conforming to the standards of a profession: professional behavior.
2. Engaging in a given activity as a source of livelihood or as a career: a professional writer.
3. Performed by persons receiving pay: professional football.
4. Having or showing great skill; expert: a professional repair job.

1. A person following a profession, especially a learned profession.
2. One who earns a living in a given or implied occupation: hired a professional to decorate the house.
3. A skilled practitioner; an expert.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.