1.  plainness(n = noun.state) - the state of being unmixed with other material; "the plainness of vanilla ice cream"
is a kind of pureness, purity
Derived form adjective plain₄

2.  plainness(n = noun.attribute) perspicuity, perspicuousness - clarity as a consequence of being perspicuous;
is a kind of clarity, clearness, limpidity, lucidity, lucidness, pellucidity
Derived form adjective plain₁

3.  plainness(n = noun.attribute) - the appearance of being plain and unpretentious;
is a kind of appearance, visual aspect
has particulars: chasteness, restraint, simpleness, simplicity, austereness, severeness, severity, bareness, starkness
Derived form adjective plain₆

4.  plainness(n = noun.attribute) homeliness - an appearance that is not attractive or beautiful; "fine clothes could not conceal the girl's homeliness"
is a kind of appearance, visual aspect
Derived form adjective plain₇

   The quality or state of being plain. [1913 Webster]

N  plainness, simplicity, severity, plain terms, plain English, Saxon English, household words, plain, simple, unornamented, unadorned, unvarnished, homely, homespun, neat, severe, chaste, pure, Saxon, commonplace, matter-of- fact, natural, prosaic, dry, unvaried, monotonous, in plain terms, in plain words, in plain English, in plain common parlance, point-blank.

N  simplicity, plainness, homeliness, undress, chastity, simple, plain, homely, homespun, ordinary, household, unaffected, ingenuous, sincere (artless), free from affectation, free from ornament, simplex munditiis, sans facon, en deshabille, chaste, inornate, severe, unadorned, bare, unornamented, undecked, ungarnished, unarranged, untrimmed, unvarnished, bald, flat, dull, veritatis simplex oratio est.

N  manifestation, plainness, plain speaking, expression, showing, exposition, demonstration, exhibition, production, display, show, showing off, premonstration, exhibit, indication, publicity, disclosure, openness panchement, evidence, manifest, apparent, salient, striking, demonstrative, prominent, in the foreground, notable, pronounced, flagrant, notorious, arrant, stark staring, unshaded, glaring, defined, definite, distinct, conspicuous, obvious, evident, unmistakable, indubitable, not to be mistaken, palpable, self-evident, autoptical, intelligible, plain, clear, clear as day, clear as daylight, clear as noonday, plain as a pike staff, plain as the sun at noon-day, plain as the nose on one's face, plain as the way to parish church, explicit, overt, patent, express, ostensible, open, open as day, naked, bare, literal, downright, undisguised, exoteric, unreserved, frank, plain-spoken, candid (veracious), barefaced, manifested, disclosed, capable of being shown, producible, inconcealable, unconcealable, no secret, manifestly, openly, before one's eyes, under one's nose, to one's face, face to face, above board, cartes sur table, on the stage, in open court, in the open streets, in market overt, in the face of day, face of heaven, in broad daylight, in open daylight, without reserve, at first blush, prima facie, on the face of, in set terms, cela saute aux yeux, he that runs may read, you can see it with half an eye, it needs no ghost to tell us, the meaning lies on the surface, cela va sans dire, res ipsa loquitur, clothing the palpable and familiar, fari quae sentiat, volto sciolto i pensieri stretti, you don't need a weatherman to know which way the.