noun. A famous lookalike. Kind of like your mom and John Goodman.
Real citation: "@tjaugustin You're tweeting your celebu-twin! That's too mind-warpy!"
(June 21, 2010, Alexander Saleh, Twitter, http://twitter.com/LosAngelic/status/16679084168)
Made-up citation: "If I had a celebu-twin, maybe I'd finally get some use out of my celebu-dungeon and celebu-bayonet. Alas!"