Blaa face

n.

An especially hurtful and derogatory comment. Also Blaa head.

In use

Get lost ye big blaa face, ye blaa head ye!

Let Lawrence Muck translate it to posh English for you
Lawrence Muck

Ah, a seeker of knowledge. Would you like me to translate 'Blaa face' in use for you?

Begone, you great bread roll of a face, you blaa head, you!