A blantantly and painfully obvious consequence or result. A result so incredibly predictable that an expectation of another result is just plain stupid or dumb.

Term can be replaced with "of course stupid" or "you should be smacked"
That Suzie's was truly surprised and agast that she was fired after she lost the most confidential records of her company's key client while visiting her best friend--- who works for the client's competition---was a "duhism."
by Jucinda L. Fenn May 7, 2005
Get the duhism, duh-ism mug.