plain

About 27.79 uses per million words.

Meaning

adjective Flat, level. .mw-parser-output .defdate{font-size:smaller}
adjective Simple, unaltered.
He was dressed simply in plain black clothes.
adjective Ordinary; lacking adornment or ornamentation; unembellished.
He was dressed simply in plain black clothes.
adjective Of just one colour; lacking a pattern.
a plain pink polycotton skirt
adjective Simple in habits or qualities; unsophisticated, not exceptional, ordinary.
They're just plain people like you or me.
adjective Having only few ingredients, or no additional ingredients or seasonings; not elaborate, without toppings or extras.
Would you like a poppy bagel or a plain bagel?
adjective Containing no extended or nonprinting characters (especially in plain text).
adjective Obvious.
His answer was just plain nonsense.