Quite possibly the best comment I have ever received on this blog. An alternative explanation of "maadi" from an anonymous commenter :
"in punjabi " maa-di" has a very different connotation. The correct usage is "teri maa-di". It can be used to start as well as end arguments. It can also be used in the middle of an argument just before fistcuffs replace vocal cords. It is a very versatile phrase and can also be adapted to other situations - greeting, salutation, frustrations. But mostly it is a a unhappy and angry phrase, that blames 'yo mamma' for all that is wrong in this world."