Name given to a person who the does one of the dumbest fucking things you've ever seen. Originated from a kid named Miles "O'Shaugnessy" Mohay and the theft of the word Knuck Knuck from some kid's big brother. One can also "Knuck Fuck", the extreme connotation of the word.
Ho-ly Shit, EJ is the biggest Knuck Knuck O'Shaugnessy I have ever seen.
I'd have to say Mandi is definetly a Knuck Knuck O'Shaugnessy...she lived her entire life thinking blinkers were called "tinkees"...she stupid, but she's hot.