/spek"yeuh leuhm/ , n. , pl. specula /-leuh/ , speculums .
1. a mirror or reflector, esp. one of polished metal, as on a reflecting telescope.
2. See speculum metal .
3. Surg. an instrument for rendering a part accessible to observation, as by enlarging an orifice.
4. Ornith. a lustrous or specially colored area on the wings of certain birds.
[ 1590-1600; spec ( ere ) to look, behold + -ulum instrumental suffix; see -ULE ]