Etymograph

English

subplane

From sub- + plane.

Formed from sub- + plane

Proto-Indo-European *upó ‘up; from below’

Proto-Italic *supo ‘under’

Latin sub ‘under, beneath, below’

English sub-

Proto-Indo-European *pleh₂- ‘flat’

Proto-Indo-European *pl̥h₂nós

Proto-Italic *plānos

Latin plānus ‘plain’

Latin plānum ‘flat surface’

English plane

Today it means

noun A plane making up part of another plane.

Sources

Sources: Wiktionary, “subplane”. 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 / subplane

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