be of unsound mind
To have impaired or dysfunctional thought, memory, or cognitive understanding; unable to think or understand for oneself. My poor grandfather has been of unsound mind ever since he suffered that stroke last year. I've been so sleep deprived lately that it feels like I'm of unsound mind! You can't tell people you want to start a business selling bees as pets—they'll think you're of unsound mind!
of unsound mind
Having impaired or dysfunctional thought, memory, and/or cognitive understanding; unable to think and/or understand for oneself. My poor grandfather has been of unsound mind ever since he suffered that stroke last year.
Farlex Dictionary of Idioms. © 2024 Farlex, Inc, all rights reserved.