plain - noun

extensive tract of level open land

a basic knitting stitch

plain - verb

• express complaints, discontent, displeasure, or unhappiness

plain - adjective

• not elaborate or elaborated; simple
• lacking patterns especially in color
• clearly revealed to the mind or the senses or judgment
• not mixed with extraneous elements
• free from any effort to soften to disguise
• lacking embellishment or ornamentation
• lacking in physical beauty or proportion

plain - adverb

• unmistakably (`plain' is often used informally for `plainly')

plain - thesaurus

apparent   apparently   bare   champaign   complain   evident   evidently   field   homely   kick   knit   kvetch   manifest   manifestly   obviously   patent   patently   plainly   quetch   sheer   spare   unembellished   unmingled   unmistakable   unmixed   unornamented   unpatterned   unvarnished