Plain or plane?
plain is an adjective meaning “Ordinary; lacking adornment or ornamentation; unembellished”; plane is an adjective meaning “Of a surface: flat or level”. They sound the same (/pleɪn/). In written English (wordfreq, 2021 data) plane is about 1.9 times as common as plain.
What is the difference between plain and plane?
| plain | plane | |
|---|---|---|
| Part of speech | adjective, adverb, noun, verb | adjective, noun, verb |
| Meaning | Ordinary; lacking adornment or ornamentation; unembellished Of just one colour; lacking a pattern colloquialSimply | Of a surface: flat or level A level or flat surface A flat surface extending infinitely in all directions (e.g. horizontal or vertical plane); a bounded portion thereof |
| Example | He was dressed simply in plain black clothes | astral plane |
| Forms | plainer, plainest | planer, planest |
| Pronunciation | /pleɪn/ [pl̥eɪn] /plen/ | /pleɪn/ |
| In writing | 27 times per million words | 52 times per million words |
Sources: plain and plane in the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Every current meaning of plain and plane
plain
- 1
Ordinary; lacking adornment or ornamentation; unembellished
He was dressed simply in plain black clothes
- 2
colloquialSimply
It was just plain stupid
- 3
An expanse of land with relatively low relief and few trees, especially a grassy expanse
- 4
Of just one colour; lacking a pattern
a plain pink polycotton skirt
- 5
A broad, flat expanse in general, as of water
- 6
Simple in habits or qualities; unsophisticated, not exceptional, ordinary
They're just plain people like you or me
- 7
Having only few ingredients, or no additional ingredients or seasonings; not elaborate, without toppings or extras
Would you like a poppy bagel or a plain bagel?
- 8
Containing no extended or nonprinting characters (especially in plain text)
plane
- 1
Of a surface: flat or level
- 2
A level or flat surface
- 3
A tool for smoothing wood by removing thin layers from the surface
- 4
To smooth (wood) with a plane
- 5
An airplane; an aeroplane
on a plane
- 6
To move in a way that lifts the bow out of the water
- 7
A deciduous tree of the genus Platanus
- 8
Dated spelling of plane (“airplane; aeroplane”)
Source: the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); obsolete, archaic, dialect and rare senses left out.
Which is more common, plain or plane?
plain appears 27 times per million words; plane 52 times per million words.
plain 27 times per million wordsplane 52 times per million words
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How many people search plain vs plane?
“plain vs plane” is searched about 3,600 times a month on Google and 100 on Bing in the United States. Google counts close variants of a query together (“plane vs plain”, “plain or plane”).
Sources: Google Ads keyword data through DataForSEO and Microsoft Advertising keyword data through DataForSEO, the average month from September 2025 to August 2026.