In a Sherlock Holmes story, he calls his profession his "metier". This is of French origin, and I haven't
seen it for quite a while.

M'etier \M['e]`tier"\, n. [F.]
Calling; vocation; business; trade.

Not only is it the business of no one to preach the
truth but it is the m['e]tier of many to conceal it.
--A. R.
Colquhoun