Plain | Webster's Dictionary (1865)

Plāin, a.

adjective

a. [compar. PLAINER; superl. PLAINEST.] [Fr. plain, Pr. plan, Sp. plano, llano, Pg. plano, It. piano, Lat. planus.]

Sense 1. Without elevations or depressions; smooth; level; even; flat;—the same as PLANE.

The sovereign weed between two marbles plain She pounded small. Spenser.

Sense 2. Open; clear; unencumbered; uninterrupted.

Our troops beat an army in plain fight and open field. Felton.

Sense 3. Not intricate or difficult; evident; manifest; obvious; unmistakable.

Why, ’tis a plain case. Shak.

One of them is a plain fish. Shak.

Sense 4. Simple; natural; as, (a.) Void of extraneous beauty or ornament; sometimes, homely; as, a plain countenance. (b.) Not highly cultivated; unsophisticated; common. “Plain people.” A. Lincoln. (c.) Void of affectation or disguise; artless; honest; frank; open; as, a plain character.

Give me leave to be plain with you. Bacon.

(d.) Not luxurious; free from costliness; not rich; as, a plain diet. (e.) Not ornamented with colors or figures; as, a plain pattern of cloth. (f.) Not much varied by modulations; as, a plain tune.

In plain, in plain terms; in fact; clearly.

Synonyms—Manifest; even; level; flat; smooth; open; artless; unaffected; undisguised; frank; sincere; honest; candid; ingenuous; unvarnished; unembellished; downright; unreserved; clear; simple; distinct; obvious; apparent. See MANIFEST.

Plāin, adv.

adverb

In a plain manner.

Plāin, n.

noun

n. [Fr. plaine, Pr., Sp., & Pg. plana, It. piano, pianura. See supra.]

Sense 1. Level land;—usually, an open field with an even surface, or a surface little varied by inequalities; as, all the plain of Jordan.

Him the Ammonite Worshiped in Rabba and her watery plain. Milton.

Sense 2. A field of battle. Arbuthnot.

Lead forth my soldiers to the plain. Shak.

Plāin, v. t.

verbtransitive

[imp. & p. p. PLAINED; p. pr. & vb. n. PLAINING.]

To level; to make plain or even on the surface. We would take Europe rather, plain the East. Wither.
To lament; to complain of. [Obs. or poet.] Chapman. Spenser.

Plāin, v. i.

verbintransitive

v. i. [Fr. plaindre, Pr. planher, Sp. planger, plañir, It. piangere, Lat. plangere.] To lament; to complain. [Obs. or poet.]