crazy uncle in the attic

[vmtnezgil]

What´s exactly the meaning of this idiom? is it used in the US, UK or both?

 

[Kasiko]

I think it means something like a ''Black sheep'' or a relative that makes you feel kind of ashamed.
Let's wait for some native speakers to opine.

 

[onbalance]

What´s exactly the meaning of this idiom? is it used in the US, UK or both?

Se usa en los EEUU. No sé si se usa en el Reino Unido. Quiere decir "black sheep." No es común.