Available Definitions:
1) v. i. - To lament; to bewail; to complain.
2) v. t. - To lament; to mourn over; as, to plain a loss.
3) superl. - Without elevations or depressions; flat; level; smooth; even. See Plane .
4) superl. - Open; clear; unencumbered; equal; fair.
5) superl. - Not intricate or difficult; evident; manifest; obvious; clear; unmistakable.
6) superl. - Void of extraneous beauty or ornament; without conspicious embellishment; not rich; simple.
7) superl. - Not highly cultivated; unsophisticated; free from show or pretension; simple; natural; homely; common.
8) superl. - Free from affectation or disguise; candid; sincere; artless; honest; frank.
9) superl. - Not luxurious; not highly seasoned; simple; as, plain food.
10) superl. - Without beauty; not handsome; homely; as, a plain woman.
11) superl. - Not variegated, dyed, or figured; as, plain muslin.
12) superl. - Not much varied by modulations; as, a plain tune.
13) adv. - In a plain manner; plainly.
14) a. - Level land; usually, an open field or a broad stretch of land with an even surface, or a surface little varied by inequalities; as, the plain of Jordan; the American plains, or prairies.
15) a. - A field of battle.
16) v. - To plane or level; to make plain or even on the surface.
17) v. - To make plain or manifest; to explain.