Speculum

Chamber's Twientieth Century Dictionary · 1908 · p. 101

spek′ū-lum, n. ( opt. ) a reflector usually made of polished metal: ( surg. ) an instrument for bringing into view parts otherwise hidden: an ocellus or eye-spot, the mirror of a wing: a lookout place:— pl. Spec′ula . [L.,— specĕre , to look.]