Lewis Short
(adjective) = ὀπισθόγραφος: ŏpisthogrăphus, a, um
* Written on the back (as, of the paper, etc.), opisthographic (post-Aug.): commentarii,Plin. Ep. 3, 5, 17.—Subst.: ŏpisthogrăphum, i, n., that which has been written upon on the back: testari in opisthographo,Dig. 37, 11, 4.
Charlton T. Lewis, Charles Short, A Latin Dictionary