The act of fitting a lot of crap into a very tiny space through clever usage of every bit of available space. Tetris-gifted people can easily pack an entire house into the trunk of a Toyota. This can come in very handy when space is at a premium!
A person who is particularly talented in this way is often referred to as a Tetris King or Queen.
I spent three hours Tetrising, but I finally got the car packed. I told you the whole living room could fit in the van in one trip!
I don't know how that girl did it, but there's thirty plastic flamingos in my bathroom!
We told you not to piss Sarah off. She's too good at Tetrising!