Lewis Short
(adjective) : spĕcŭlātīvus, a, um, id.
* Speculative (late Lat.): philosophia, Boëth. ap. Porphyr. Dial. 1, p. 2.—Hence, subst.: spĕcŭlātīva, ae, f., = contemplativa (sc. philosophia), Cassiod. Var. 1, 45.
Charlton T. Lewis, Charles Short, A Latin Dictionary