A series of assumptions that start with "I think" which is twisted to "it's a fact".
When an uneducated opinion starts with "I don't think he's a racist" and turns to fact, "I know for a fact that he's not a racist". Then it's time to label the offending fucktard
The act of being so drunk you cant stand up or talk.
Look at that guy, he's all stumblefuck.
A person that falls or trips frequently.
Someone that injured themselves by falling or tripping.
pointing out the arrival of someone who recently hurt themselves in a fall-
"Oh look, here comes Stumblefuck"