Personal Definition of Professional: 

One's commitment to their career and determination to succeed and go beyond on any task at hand. 

Professionalism not only describes that you should handle yourself in a respectful manner, (Such as arriving to work on time, communicating politely with others, work ethic, etc.), but should have the determination to become better at your job every single day. 

To be a professional, in my opinion, is to enjoy every step of the process, as one cannot be successful if they do not enjoy coming to work.