An
instrument inserted into the
body so that
internal areas can be inspected. Traditionally, a medical speculum has two "blades" which are attached to each other at one end, and can be inserted into an orifice and then spread apart to hold that orifice open. (There is a relatively new four-blade vaginal speculum on the market as well.)
Most commonly heard of in connection with women's gynecology exams, where a speculum is used to hold the walls of the vagina apart so that pap smear samples and such can be taken from the cervix. A different design of speculum is also used in eye surgery procedures (such as LASIK) to hold the eye open. A Google search also finds references to nasal, ear, and rectal specula.
Speculum is also a journal published by the Medieval Academy of America, printing articles on "all fields of medieval studies." The journal, founded in 1926, was the first North American scholarly journal devoted only to medieval studies, and includes studies of approximately A.D. 500-1500, primarily focusing on Western Europe, but Byzantine, Hebrew, Arabic, and Slavic studies are also included.
http://www.medievalacademy.org/www/speculum.htm