n. (pl. specula)
1. Surgery an instrument for dilating the cavities of the human body for inspection.
2 a mirror, usu. of polished metal, esp. in a reflecting telescope.
3 Ornithol. a lustrous coloured area on the wing of some birds, esp. ducks.
Phrases and idioms:
speculum-metal an alloy of copper and tin used as a mirror, esp. in a telescope.
Etymology: L, mirror, f. specere look