Crazy as a coot/loon informal simile spoken
The phrase is often used jocularly.
Insane or weird.
Don't leave me alone with Mark- he's crazy as a coot!
If you think you can get away with that, you are as crazy as a loon.
Mr. John's bald, so why did you buy him a hair brush? You are as crazy as a coot!
Extremely stupid
Very stupid, or silly
Stupid or crazy
To be extremely stupid; not to be alert
If you're off your trolley, your ideas or behaviour are crazy or insane.
The simile to the water bird stems from the sixteenth century.
Come out of a difficult situation without a stain on one's character
I don't understand how he can fall in shit and come out smelling like a rose.