a piece of mind

a piece of (one's) mind

One's true thoughts or feelings about something, especially angry or frustrated criticism. Boy, the boss really gave me a piece of his mind during my performance review. This has to have been the worst service I've ever had a restaurant. I'm going to let the waiter have a piece of my mind!
See also: mind, of, piece

a piece of (one's) mind

Frank and severe criticism; censure.
See also: mind, of, piece