1 definition by MAP08

A one-upper who always has to be bigger or better than you. If your uncle has 20 ft. boat, his uncle or cousin has 21 ft. boat. A one-upper never loses in the world of story-telling.
Chris is a nice guy, but he's a big one-upper. He always follows my stories with a better one!
by MAP08 July 5, 2007
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