Lewis & Short

lā̆trōcĭnālis, e, adj. [2. latro, II.], of or belonging to robbers, robber- (post-class.): manus, a band of robbers, App. M. 2, p. 125, 5: castra, Amm. 27, 2.
Hence, adv.: lă-trōcĭnālĭter, after the manner of a robber, like a robber: aliquem interimere, Mart. Cap. 6, § 642.