e.g. She was very professional during the meeting and conducted affairs very efficiently.
e.g. This is her first role as a professional actress.
e.g. The car was driven by a professional commuting to work. He aspires to become a professional who competes in international sporting events.
e.g. He is a professional at playing the drums.
"Being a professional is doing all the things you love to do on the days you don't feel like doing them." -- Julius Erving