Mystery
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
A trade, art or occupation.
2 Inst. 668.
Masters frequently bind themselves in the indentures with their apprentices to teach them their art, trade, and mystery.
State v. Bishop, 15 Me. 122; Barger v. Caldwell, 2 Dana (Ky.) 13L