plain1

adjective

• 1not decorated or elaborate; simple or basic in character:good plain food everyone dined at a plain wooden table
• without a pattern; in only one colour:a plain fabric
• bearing no indication as to contents or affiliation:donations can be put in a plain envelope
• (of paper) without lines.

• 2easy to perceive or understand; clear:the advantages were plain to see it was plain that something was wrong
• [attributive] (of written or spoken usage) clearly expressed, without the use of technical or abstruse terms:an insurance policy written in plain English
• not using concealment or deception; frank:there were indrawn breaths at such plain speaking

• 3not distinguished by any particular beauty; ordinary looking:a plain, round-faced woman
• having no pretensions; not remarkable or special:a plain, honest man with no nonsense about him

• 4 [attributive] sheer; simple (used for emphasis):the main problem is just plain exhaustion

• 5(of a knitting stitch) made by putting the needle through the front of the stitch from left to right. Compare with purl¹.

adverb

• 1 [as submodifier] used for emphasis:perhaps the youth was just plain stupid

• 2clearly or unequivocally:I’m finished with you, I’ll tell you plain

noun

• a large area of flat land with few trees: the coastal plain