English
planar
Planar comes from Late Latin plānārius ‘relating to a plane’, from Latin plānus ‘flat”, “level’, and perhaps ultimately from Proto-Indo-European *pleh₂-.
- Proto-Indo-Europeanc. 4500–2500 BCE*pleh₂-1‘flat’uncertain
- Proto-Indo-Europeanc. 4500–2500 BCE*pl̥h₂nós1reconstructed
- Proto-Italicc. 1500–700 BCE*plānos1reconstructed
- Latinc. 75 BCE–200 CEplānus2‘flat”, “level’
- Late Latinc. 200–600 CEplānārius2‘relating to a plane’
- Englishtodayplanar2
attested reconstructed ? uncertain or disputed deepest recorded ancestor
- 1 Wiktionary, Latin planus
- 2 Wiktionary, English planar
Lineage
- Proto-Indo-Europeanc. 4500–2500 BCE*pleh₂-Wiktionary, Latin planus‘flat’uncertain
- Proto-Indo-Europeanc. 4500–2500 BCE*pl̥h₂nósWiktionary, Latin planusreconstructed
- Proto-Italicc. 1500–700 BCE*plānosWiktionary, Latin planusreconstructed
- Latinc. 75 BCE–200 CEplānusWiktionary, English planar‘flat”, “level’
- Late Latinc. 200–600 CEplānāriusWiktionary, English planar‘relating to a plane’
- EnglishtodayplanarWiktionary, English planar
Linked words
through Proto-Indo-European *pleh₂- ‘flat’
field, floor, palm, planet, clan, fluke, archipelago, flounder, parma, placenta, playa, palatine, lech, polonium, pelagic, placate, veld, implacable, flay, floe, purdah, plantar, planta, 46 more
through Proto-Italic *plānos
unexplainable, explainable, 11 more
through Latin plānus ‘flat”, “level’
explain, plane, plain, explanation, explanatory, esplanade, llano, 14 more
Today it means
adj Of or pertaining to a plane.
Sources
Sources: Wiktionary, “planar”; the older steps come from the Wiktionary entry for Latin planus. 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 *pleh₂- / planar