Another way of saying shut up, be quiet, shut your mouth.
Frank: Meh meh meh
A vech is a title for a person that can be used in any situation. For example, it can be used to describe someone who is complaining, bitchy, annoying, boring, etc.
It is one of those words that you can label absolutely anyone with. It can be offensive or funny, light hearted or derogatory.
Frank is a vech, he's always trying to get attention
When Justine gets drunk she acts like such a vech