Cilium
/ˈsɪliəm/noun
A slender hair-like structure, especially one of the tiny hairs lining certain cells or surfaces.
Did you know?The Latin root cilium originally meant “eyelid” or “eyelash,” and that same body-part word later gave us the scientific term for the hairlike structures that seem to sweep the cell like invisible little lashes.
Etymological Timeline
Proto-Indo-European
PIE
*kel-
“to cover, conceal; a root associated with covering or sheltering”
Latin
Latin
cilium
“eyelid; eyelash”
Late Latin
Latin
cilia
“eyelashes; fine hairs”
17th Century
New Latin
cilium
“a hairlike anatomical structure”
Modern English
English
cilium
“a tiny hairlike projection on a cell or organism”