Depends opn usage of the word. Technically a " professional" bases income on said profession.Pretty cut and dry.

The word " pro" or " Professional" also can be used loosely, generally in a complimentry way, to mean someone that conducts themselves in a way that denotes a certain standard, or holds to a level above the norm.

As the chef/owner of a restaurant. I am a " proffesional" Chef. If a guset asks me for no chives in his Potato chowder and I tell him his mama wears combat boots....that would' t be very professional.