A form of retaliation against someone who has wronged you in some way.
Mama Birdin' is when you chew up some food and spit it in someone elses mouth. The is especially effective if you wait for the person you're going to mama Bird to fall asleep and their mouth is open. This gives you the element of surprise.
My brother borrowed my car the other night and left me with almost not gas so I'm Mama Birdin' him tonight when he's in bed.
When an otherwise functional person does something retarded and realizes it they have gone tarded.
I was inside the house cooking up some meth when all the sudden I smelled smoke on the porch. I immediately went to investigate and saw a flaming bag of poo. I stepped on it to put it out and immediately knew I had just "gone tarded."