plain vs llano

plain and llano both are nouns.

Word	Noun	Adjective	Verb	Adverb
plain	Yes	Yes	Yes	Yes
llano	Yes	No	No	No

As nouns, llano is a hyponym of plain; that is, llano is a word with a more specific, narrower meaning than plain:

plain: extensive tract of level open land
llano: an extensive grassy and nearly treeless plain (especially in Latin America)

Other hyponyms of plain include flat, flood plain, floodplain, moor, moorland, peneplain, peneplane, snowfield, steppe, tundra.

plain (noun)	llano (noun)
a basic knitting stitch made by putting the needle through the front of the stitch from the lefthand side	an extensive grassy and nearly treeless plain (especially in Latin America)
extensive tract of level open land

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

plain (verb)	llano (verb)
express complaints, discontent, displeasure, or unhappiness

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