English
planum
Planum comes from Latin plānum ‘level ground, plain’, and perhaps goes back to Proto-Indo-European *pleh₂- ‘flat’.
- 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, even, level’
- Latinc. 75 BCE–200 CEplānum3‘level ground, plain’
- Englishtodayplanum3
attested reconstructed ? uncertain or disputed deepest recorded ancestor
- 1 Wiktionary, Latin planus
- 2 Wiktionary, Latin planum
- 3 Wiktionary, English planum
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, Latin planum‘flat, even, level’
- Latinc. 75 BCE–200 CEplānumWiktionary, English planum‘level ground, plain’
- EnglishtodayplanumWiktionary, English planum
Linked words
through Proto-Indo-European *pleh₂- ‘flat’
field, floor, palm, planet, clan, archipelago, fluke, parma, flounder, placenta, playa, palatine, lech, pelagic, placate, veld, polonium, implacable, flay, floe, purdah, plantar, planta, 45 more
through Proto-Italic *plānos
unexplainable, explainable, 10 more
through Latin plānus ‘flat, even, level’
explain, explanation, explanatory, planar, esplanade, llano, 13 more
through Latin plānum ‘level ground, plain’
Today it means
noun any flat surface
Sources
Sources: Wiktionary, “planum”; the older steps come from the Wiktionary entries for Latin planus, Latin planum. 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- / planum