a confrère
He is engrossed in his profession.
He is engrossed in his profession.
He is engrossed in his profession.
a chef who specializes in pastry
He is devoted to his profession―enthusiastic in his profession.
He is engrossed in his profession―devoted to his profession.
the act of specializing
He is engrossed in his profession.
to make a special study of―made a specialty of―make a study of―a subject
{that} field of speciality
He is engrossed in his profession.
a female employee who has a professional skill
He is engrossed in his profession.
The construction is conducted by professionals.