A combination of the words "fuck" and "shit". Usually used to express deep anger when one is pissed off to the max. Can also be used to describe an object as great, like one would say something is "the shit".
"Brad, I was driving your sister home, but we were in a terrible crash, and... I'm so sorry..."
"FUCKANDSHIT!"
"Hey, remember those Harvest Moon games we used to play?"
"Yeah man, those games were the fuckandshit."
A giant tornado carrying a fuckload of heavy materials which are ready to fall on innocent children as the FUCKNADO passes.
Holy shit! Look a FUCKNADO!!! We're all going to fucking burn in hell!!! O FUCK ITS COMING STRAIGHT FUCKING TOWARD US!!! I HAVE TO FUCKING KILL MY CHILDREN BEFORE THEY GET HURT!!!!!!!!!!!!!!!!!!!!
No, really we're in a FUCKNADO path right now.... we should have moved away... but we like our peaceful little doomed neighborhood. Oh here it comes now... bye.