A unique weapon of grammar combining words in a fashion similar to a contraction, but with three words and two apostrophes instead of two and one, respectively. Usually used by people who are too important to speak with any normal regard for english.
"I wouldn't've used a double contraction."
"I'd've told you about double contractions, but I would have had to kill you."
Misspronounciation of the Gigawatt measurement of energy, most famously used in the film Back To The Future (1985) in a discussion between Doc Brown and Marty McFly on the subject of powering the doctor's freaking awesome DeLorean.