Dictionary.com
definitions

plain

1
[pleyn]
See more synonyms for plain on Thesaurus.com
adjective, plain·er, plain·est.
  1. clear or distinct to the eye or ear: a plain trail to the river; to stand in plain view.
  2. clear to the mind; evident, manifest, or obvious: to make one's meaning plain.
  3. conveying the meaning clearly and simply; easily understood: plain talk.
  4. downright; sheer; utter; self-evident: plain folly; plain stupidity.
  5. free from ambiguity or evasion; candid; outspoken: the plain truth of the matter.
  6. without special pretensions, superiority, elegance, etc.; ordinary: plain people.
  7. not beautiful; physically unattractive or undistinguished: a plain face.
  8. without intricacies or difficulties.
  9. ordinary, simple, or unostentatious: Although she was a duchess, her manners were attractively plain.
  10. with little or no embellishment, decoration, or enhancing elaboration: a plain blue suit.
  11. without a pattern, figure, or device: a plain fabric.
  12. not rich, highly seasoned, or elaborately prepared, as food: a plain diet.
  13. flat or level: plain country.
  14. unobstructed, clear, or open, as ground, a space, etc.
  15. Cards. being other than a face card or a trump.
adverb
  1. clearly and simply: He's just plain stupid.
noun
  1. an area of land not significantly higher than adjacent areas and with relatively minor differences in elevation, commonly less than 500 feet (150 meters), within the area.
  2. The Plains. Great Plains.

Origin of plain

1
1250–1300; Middle English (adj., adv., and noun) < Old French (adj. and noun) < Latin plānus flat, level, plānum flat country
Related formsplain·ly, adverbplain·ness, noun
Can be confusedplain plan plane

Synonym study

10. See homely.

Synonyms for plain

See more synonyms for on Thesaurus.com
1, 2. lucid, understandable, intelligible, unmistakable, apparent, perspicuous. 2, 3. unambiguous, unequivocal, patent, transparent; direct. 5. unreserved, straightforward, blunt, frank, ingenuous, open, sincere. 6. unpretentious. 10. unadorned.

Antonyms for plain

1. indistinct. 2. obscure. 13. hilly.

plain

2
[pleyn]
verb (used without object) British Dialect.
  1. to complain.

Origin of plain

2
1250–1300; Middle English plei(g)nen < Old French plaign-, stem of plaindre < Latin plangere to beat (the breast, etc.), lament; akin to Greek plḗssein to strike
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for plain

transparent, honest, simple, traditional, ordinary, conventional, dull, unvarnished, austere, stark, pure, meadow, expanse, field, prairie, steppe, grassland, plateau, patent, broad

Examples from the Web for plain

Contemporary Examples of plain

Historical Examples of plain

  • The track was plain enough, and there were hamlets at long intervals.

    The Armourer's Prentices

    Charlotte M. Yonge

  • A plain case, that he had left his curiosity with me, and designed to shew me no other.

    Clarissa, Volume 1 (of 9)

    Samuel Richardson

  • Aye, lad, and the plain things are always the hardest things to do.

  • It's a shirt and a plain stocking were got off a drowned man in Donegal.

  • One thing is plain, you must either go to them, or unlock the cellar-door.

    Weighed and Wanting

    George MacDonald

British Dictionary definitions for plain

plain

1
adjective
  1. flat or smooth; level
  2. not complicated; clearthe plain truth
  3. not difficult; simple or easya plain task
  4. honest or straightforward
  5. lowly, esp in social rank or education
  6. without adornment or showa plain coat
  7. (of fabric) without pattern or of simple untwilled weave
  8. not attractive
  9. not mixed; simpleplain vodka
  10. knitting of or done in plain
noun
  1. a level or almost level tract of country, esp an extensive treeless region
  2. a simple stitch in knitting made by putting the right needle into a loop on the left needle, passing the wool round the right needle, and pulling it through the loop, thus forming a new loop
  3. (in billiards)
    1. the unmarked white ball, as distinguished from the spot balls
    2. the player using this ball
  4. (in Ireland) short for plain porter, a light portertwo pints of plain, please
adverb
  1. (intensifier)just plain tired
See also plains
Derived Formsplainly, adverbplainness, noun

Word Origin for plain

C13: from Old French: simple, from Latin plānus level, distinct, clear

plain

2
verb
  1. a dialect or poetic word for complain

Word Origin for plain

C14 pleignen, from Old French plaindre to lament, from Latin plangere to beat
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for plain
adj.

c.1300, "flat, smooth," from Old French plain "flat, smooth, even" (12c.), from Latin planus "flat, even, level" (see plane (n.1)). Sense of "evident" is from, c.1300; that of "free from obstruction" is early 14c.; meaning "simple, sincere, ordinary" is recorded from late 14c., especially of dress, "unembellished, without decoration."

In reference to the dress and speech of Quakers, it is recorded from 1824; of Amish and Mennonites, from 1894 (in the Dutch regions of Pennsylvania Plain with the capital is shorthand adjective for "Amish and Old Order Mennonite"). Of appearance, as a euphemism for "ill-favored, ugly" it dates from 1749. Of envelopes from 1913. As an adverb from early 14c. Plain English is from c.1500. Plain dealer "one who deals plainly or speaks candidly" is from 1570s, marked "Now rare" in OED 2nd edition. To be as plain as the nose on (one's) face is from 1690s.

n.

"level country," c.1300 (in reference to Salisbury Plain), from Old French plain "open countryside," from Latin planum "level ground, plain," noun use of neuter of planus (adj.) "flat, even, level" (see plane (n.1)). Latin planum was used for "level ground" but much more common was campus.

Online Etymology Dictionary, © 2010 Douglas Harper
plain in Science

plain

[plān]
  1. An extensive, relatively level area of land. Plains are present on all continents except Antarctica and are most often located in the interior regions. Because they can occur at almost any altitude or latitude, plains can be humid and forested, semiarid and grass-covered, or arid.
  2. A broad, level expanse, such as an area of the sea floor or a lunar mare.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Idioms and Phrases with plain

plain

In addition to the idioms beginning with plain

  • plain as day
  • plain sailing

also see:

  • in plain English
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.