English
cilium
Cilium comes from Latin cilium ‘eyelid’, and goes back to Proto-Indo-European *ḱel- ‘to cover’.
- Proto-Indo-Europeanc. 4500–2500 BCE*ḱel-1‘to cover’reconstructed
- Proto-Indo-Europeanc. 4500–2500 BCE*ḱelyom1reconstructed
- Proto-Italicc. 1500–700 BCE*keljom1reconstructed
- Latinc. 75 BCE–200 CEcilium1‘eyelid’
- Englishearliest quotation 1892cilium1
attested reconstructed ? uncertain or disputed deepest recorded ancestor
- 1 Wiktionary, English cilium
- Earliest quotation in Wiktionary’s entry: 1892, Carl Friedrich Wilhelm Claus: “It is the deeper parts of such cells which…”.
Lineage
- Proto-Indo-Europeanc. 4500–2500 BCE*ḱel-Wiktionary, English cilium‘to cover’reconstructed
- Proto-Indo-Europeanc. 4500–2500 BCE*ḱelyomWiktionary, English ciliumreconstructed
- Proto-Italicc. 1500–700 BCE*keljomWiktionary, English ciliumreconstructed
- Latinc. 75 BCE–200 CEciliumWiktionary, English cilium‘eyelid’
- Englishearliest quotation 1892ciliumWiktionary, English cilium. Earliest quotation in Wiktionary’s entry: 1892, Carl Friedrich Wilhelm Claus: “It is the deeper parts of such cells which…”
Linked words
through Proto-Indo-European *ḱel- ‘to cover’
hell, color, cell, hall, hole, holder, hull, helmet, hollow, halt, ceiling, helm, holden, conceal, uphold, occult, clandestine, sari, sala, declension, tricolour, recline, declination, haugh, halberd, hele, holing, 36 more
through Latin cilium ‘eyelid’
Today it means
noun A short microscopic hairlike organelle projecting from a eukaryotic cell (such as a unicellular organism or one cell of a multicelled organism) which serve either for propulsion by causing currents in the surrounding fluid or as sensors.
Sources
Sources: Wiktionary, “cilium”. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.
Etymograph / Proto-Indo-European *ḱel- / cilium