Lewis & Short

fŏrinsĕcus, adv. [foris + secus, analogous with extrin-secus]. from without, on the outside, = ἔξωθεν (post-Aug.).

  1. I. Lit.: ab cohorte forinsecus praedictis fenestellis, Col. 8, 3, 6: quarundam naturae lignum omne corticis loco habent, hoc est forinsecus, Plin. 13, 22, 42, § 122: non forinsecus, ut cetera, sed interius armavit, Lact. Opif. D. 2, 9: si actionem diuturnam, quae est forinsecus expedita, perquiras, i. e. publicly, Sid. Ep. 1, 2: decursae actiones, id. ib. 3, 1.
  2. II. Transf., for foras, out of doors, out: plagis castigatum forinsecus abicit, App. M. 9, p. 230, 15; 3, p. 138, 33.