The term "Hickory Dickory Clock" refers to a clock made from hickory (or other types of wood) that has penis shaped hands, or other phallic themed decorations. The "Hickory" suggests the clock must be wooden for this title to apply, while the "Dickory" points to the genitalia decorations. The original hickory dickory clock's whereabouts are unknown, however the second ever crafted resides in paris.
Jamie: "Wow, I love your hickory dickory clock! The shape of the hands really turn me on..."
Niko: "Thank you! And yeah, looking at it turns me on too..."
Jamie: "You should show me your hickory dickory cock big boy."
Niko: "OK."
Word made up by Devin that proably has to do with something dirty. Also could be a misspelling of dictionary, or about the tyranny of d**ks. Hard to say, but in this case I'm sure it's urban. (:
Devin: "Lol got to love urban dictorany. Looked up my name. Made me laugh so much"