A combination of the words 'shit' and 'burrito'. It explains a situation or day that made you feel worse than eating a bad burrito. It can also be used to explain food that tastes worse than a bad burrito.
How was your daytoday?
Oh, my day was absolutely sherito. Have you had lunch?
Yes, my burger tasted sherito!
The unwelcome mist that greets you when you sit on a poorly functioning self-flushing toilet that flushes after you sit down instead of when you stand up.
I sat down to drop a few friends in the pool, and got a nasty rectal shpritz.