The plain meaning of the word "plain" is an unadorned or simple surface, often referring to something that is not decorated or embellished. It can also refer to a level area of land that is relatively flat and free from obstructions.
Usage examples
I prefer plain yogurt over flavored options.
She wore a plain black dress to the party.
The room was painted in plain white.
The instructions were written in plain English.
I ordered a plain burger with no toppings.
The book was printed in plain font, making it easy to read.
He gave a plain and simple explanation of the problem.
The hotel room was quite plain, with minimal decorations.
I like my coffee plain, without any sugar or cream.
She expressed her feelings in plain words, without any ambiguity.