Derived from the word 'unintelliGIBLE'. Refers to words people speak that make absolutely no fucking sense. Examples: baby/pet talk, Valley/Jersey Shore girls lingo, and extremely intoxicated people trying to tell you a story about "this one time" or how to fight The Man.
Nicki Minaj: "Quack quack to a duck and a chicken too / Put the hyena in a freakin' zoo!"
Fan: "What the hell, Nicki. You got a serious case of the gibbles."
grandma: awww look at my wittle jeff with da big soft gibbles yea he is
jeff: gran im 18 no...stop*blushes*
grandma:oh cmon
jeff:NOOOOOO STOPPP*DUMPS GRANDMA IN POOL*