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Definition of planar

planar

/ˈpleɪ.nɚ/
pla · nar
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planar Lexical Profile

planar Game Scores & Validity

• adjective

1

Relating to, lying in, or having the form of a geometric plane; flat or two-dimensional.

Example

"Benzene has a planar molecular structure in which all twelve atoms lie in the same flat plane."

2

Can be embedded in a plane such that its edges intersect only at their endpoints (of a mathematical graph).

Example

"According to Kuratowski's theorem, a finite graph is planar if and only if it does not contain a subgraph that is a subdivision of K5 or K3,3."

Synonyms
View all synonyms for planar
Antonyms
View all antonyms for planar

Word Nuance & Usage

Do not confuse the adjective 'planar' (meaning flat or two-dimensional) with the noun 'planer' (a woodworking tool or machine used to smooth wood surfaces).

• Rhymes for planar

• Nearby Words

plaintively
plait
plan
planar
planarian
planchette
plane

Word Origin & Etymology

Coined in the mid-19th century from Late Latin planaris ('flat, level'), derived from Latin planum ('flat surface, plane').

Cite this Entry

Wordmom. (2026). Definition of Planar. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/planar
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