Off one’s rocker.
Acting irrational or crazy.
'Off one’s rocker' is an informal way to say that someone is behaving in a crazy, absurd, or irrational manner. It evokes the image of an unstable rocking chair, suggesting a lack of mental stability or sound judgment.
Example Sentences
Everyone thought he was off his rocker for jumping into the freezing lake.
Everyone thought he was crazy for jumping into the freezing lake.
Her suggestion seemed so bizarre that people wondered if she was off her rocker.
Her suggestion seemed so bizarre that people thought she was crazy.
Trying to climb the building without ropes made him look completely off his rocker.
Trying to climb the building without ropes made him look completely crazy.