It stands for catastrophic university induced stupidity. Usage: “Bill, I got another CUIS situation here.” I came up with the phrase when I was trying to describe the situation most of us have been in, and some of us survived, when just being at a university for the first time causes a temporary (though this could get chronic) leaving of the senses such that ‘acting without thinking’ becomes the only reasonable course of action. Which in turn leads to trouble. Which results in the growing sense of “I don’t know what I was thinking.” taking over. Ken noticed the ubiquity of the term, and the need for its achronymification.