Meaning

noun a mirror (especially one made of polished metal) for use in an optical instrument

noun a medical instrument for dilating a bodily passage or cavity in order to examine the interior

originEtymology tree Proto-Indo-European *speḱ- Proto-Indo-European *-yeti Proto-Indo-European *spéḱyeti Proto-Italic *spekjō Proto-Indo-European *-tḗr Proto-Indo-European *-trom Proto-Indo-European *-tlom Proto-Italic *-klom Latin speculumlbor. English speculum Learned borrowing from Latin speculum.

Etymology from Wiktionary, CC BY-SA 3.0