Descriptive nickname applied to one's self or another, showing gratitude or exasperation at the size of their ass.
Connor: "Quick, Smiley!"
Smiley: "Huh?"
Connor: "Look!" (Points to a girl sitting in a window, with her ass hanging out of the sill) "It's amazing!"
Smiley: "No, that's marvelass!"
by Smiley (Chris) August 1, 2013
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