Lewis Short
(adjective) : artĭfĭcĭālis, e, artificium
* Of or belonging to art, artificial, according to the rules of art (perh. only in Quint.): probationes,Quint. 5, 1, 1; so id. 5, 9, 1; 12, 8, 19: ratio,id. 6, 4, 4.—Once subst.: artĭfĭ-cĭālia, ium, n., things conformable to the rules of art, Quint. 1, 8, 14.—Adv.: artĭ-fĭcĭālĭter, according to art (opp. inartificialiter): se gerere,Quint. 2, 17, 42.
Charlton T. Lewis, Charles Short, A Latin Dictionary