Barmy

Adjective / UK Slang

Barmy means crazy, eccentric, or behaving in a foolish or irrational manner. It is used to describe someone or something that is considered outlandish or nonsensical.

Example: “He’s gone completely barmy”
Means: “He’s acting very crazy or irrational.”

Example: “That idea is absolutely barmy”
Means: “That idea is completely crazy or unreasonable.”