Dictionary.com
definitions

professional

[pruh-fesh-uh-nl]
adjective
  1. following an occupation as a means of livelihood or for gain: a professional builder.
  2. of, relating to, or connected with a profession: professional studies.
  3. appropriate to a profession: professional objectivity.
  4. engaged in one of the learned professions: A lawyer is a professional person.
  5. following as a business an occupation ordinarily engaged in as a pastime: a professional golfer.
  6. making a business or constant practice of something not properly to be regarded as a business: “A salesman,” he said, “is a professional optimist.”
  7. undertaken or engaged in as a means of livelihood or for gain: professional baseball.
  8. of or for a professional person or his or her place of business or work: a professional apartment; professional equipment.
  9. done by a professional; expert: professional car repairs.
noun
  1. a person who belongs to one of the professions, especially one of the learned professions.
  2. a person who earns a living in a sport or other occupation frequently engaged in by amateurs: a golf professional.
  3. an expert player, as of golf or tennis, serving as a teacher, consultant, performer, or contestant; pro.
  4. a person who is expert at his or her work: You can tell by her comments that this editor is a real professional.

Origin of professional

First recorded in 1740–50; profession + -al1
Related formspro·fes·sion·al·ly, adverbin·ter·pro·fes·sion·al, adjectivein·ter·pro·fes·sion·al·ly, adverbpseu·do·pro·fes·sion·al, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for interprofessional

professional

adjective
  1. of, relating to, suitable for, or engaged in as a profession
  2. engaging in an activity for gain or as a means of livelihood
    1. extremely competent in a job, etc
    2. (of a piece of work or anything performed) produced with competence or skill
  4. undertaken or performed for gain or by people who are paid
noun
  1. a person who belongs to or engages in one of the professions
  2. a person who engages for his livelihood in some activity also pursued by amateurs
  3. a person who engages in an activity with great competence
  4. an expert player of a game who gives instruction, esp to members of a club by whom he is hired
Derived Formsprofessionally, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for interprofessional

professional

adj.

early 15c., of religious orders; 1747 of careers (especially of the skilled or learned trades from c.1793); see profession. In sports, opposed to amateur, from 1846. Related: Professionally.

professional

n.

"one who does it for a living," 1798, from professional (adj.).

Online Etymology Dictionary, © 2010 Douglas Harper