(adjective) : rătĭōnābĭlis, e, ratio (post-Aug.; = rationalis, which is in better use)
* Reasonable, rational: natura,Sen. Vit. Beat. 14, 1: virtutes quae ad rationabilem animum pertinent,App. Dogm. Plat. 2, p. 17, 18; cf.: virtutes rationabiles,id. ib.: responsio rationabilis,Vulg. Job, 32, 3: rationabile sine dolo lac,the pure milk of reason,id. 1 Pet. 2, 2: sententia vera et rationabilis,Dig. 5, 1, 2, § 3.—Comp.: rationabilius esse videtur,Dig. 45, 3, 37.—Adv.: rătĭō-nābĭlĭter, rationally, reasonably, App. Dogm. Plat. 1: errare,Hier. Ep. 39, 5; Macr. Somn. Scip. 2, 11, 17; Amm. 20, 4, 8; Lact. Ep. 61, 17.

s. TLL