professionalism; the temperament of a professional
Refers to the characteristic mindset, pride, or disposition of a seasoned professional, often implying a certain aloofness or strict standards.
You can sense the temperament of a true professional in the way he works.
プロ意識 is a more modern, straightforward term for 'professional awareness' or 'professional attitude', while 玄人気質 carries a traditional, almost artisanal nuance of a veteran's disposition.
Compound of 玄人 (くろうと, 'expert, professional') and 気質 (かたぎ, 'temperament, disposition'). The exact historical derivation is uncertain, but the combination straightforwardly yields 'the temperament of a professional'.