Definitions
01simple or undecorated
B1 · Intermediate
adj. simple and not decorated with patterns or extra details.
adj. lacking ornament, decoration, or pattern; simple in design or appearance.
日本語:無地の、質素な※
“He wore a plain white t-shirt and blue jeans to the party.”
“The interior was decorated in a plain, minimalist style that emphasised the architectural lines of the building rather than the furniture.”
02easy to understand
B1 · Intermediate
adj. clear and easy to see or understand.
adj. clear to the mind; easy to perceive or understand without ambiguity.
日本語:明らか※
“The truth was plain to see for everyone in the room.”
“The instructions were written in plain English to ensure that users without technical backgrounds could operate the machinery safely.”
03not attractive
B2 · Upper Intermediate
adj. not beautiful or handsome, but not ugly either.
adj. not distinguished by beauty; having a simple or unremarkable appearance.
日本語:地味※
“She described herself as a plain person who didn't like wearing makeup.”
“The protagonist was often described as a plain woman, a choice by the author to focus on her intellectual depth rather than her physical appearance.”
Synonyms
Antonyms
04flat land
B1 · Intermediate Countable noun
n. a large area of flat land with few trees.
n. an extensive area of level or gently undulating land, usually at a low elevation and often covered in grass.
“The train travelled across the vast plains for several hours.”
“The Great Plains of North America support a diverse ecosystem despite the relatively low annual rainfall and lack of natural forest cover.”
05completely or simply
B2 · Upper Intermediate Informal
adv. used to emphasize that something is completely true or simple.
adv. used as an intensifier to mean 'simply' or 'completely'; typically precedes an adjective.
“That idea is just plain stupid.”
“It was plain wrong of him to take credit for work that the entire team had contributed to over the last six months.”
Usage
Usually placed before an adjective to add emphasis.
Synonyms
Collocations
Common phrases and expressions where native English speakers use the word “plain” in context.
Verb
01. make plain that
“The manager made it plain that no further delays would be tolerated.”
verb + adj + that-clause
02. speak plain truth
“He decided to speak the plain truth rather than hiding behind complicated excuses.”
verb + adj + noun
Adjective
03. plain clothes
“The detectives were working in plain clothes to avoid being recognized by the suspects.”
adj + noun
04. plain english
“The legal contract was rewritten in plain English so that everyone could understand the terms.”
adj + noun
05. plain to see
“It was plain to see that she was unhappy with the final decision.”
adj + infinitive
06. plain yogurt
“I prefer to buy plain yogurt and add my own fresh fruit for breakfast.”
adj + noun
Noun
07. flood plain
“Building houses on a flood plain is risky because the river often overflows during heavy rain.”
noun + noun
08. vast plain
“The travelers gazed across the vast plain, which stretched for miles toward the horizon.”
adj + noun
09. plain sight
Real-World Examples
“He's not alone, from Africa's grasslands to the salt-crusted plains of Central Asia, this same story is playing out for millions of people who depend on land many people may never think about: Rangelands.” “That’s what pulled me to the plains of north-central Spain last week.” Etymology
From Middle English pleyn, borrowed from Anglo-Norman pleyn, playn, Middle French plain, plein, and Old French plain, from Latin plānus (“flat, even, level, plain”). Doublet of llano, piano, and plane.
From Old French plain, from Latin plānum (“level ground, a plain”), neuter substantive from plānus (“level, even, flat”). Doublet of llano, piano, and plane.
From Anglo-Norman plainer, pleiner, variant of Anglo-Norman and Old French pleindre, plaindre, from Latin plangere.
From Middle English pleyn, borrowed from Old French plein, from Latin plēnus (“full, filled, complete”). Ultimately from Proto-Italic plēnos, from Proto-Indo-European pl̥h₁nós (“full”). Doublet of plene, plenary, and full.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Word family
NOUN
ADJECTIVE
ADVERB
Idioms
Domain
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B2 FirstIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.5.5–6.5TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 4.0–4.572–94TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.785–944
- Frequency
- Common
- Level
- B2 · Upper IntermediateOxford
- Updated
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QR code
englishreference.com/q/plain
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「日本語」「カタカナ語」 data: JMdict (EDRDG), CC BY-SA 4.0