Out-of-date; old-fashioned; no longer current or popular; behind the times; antiquated. Reference to a time when the world was thought to be flat.
Check out my cool new bracelets. They look like rubber bands on my wrist but when you take them off, they are in the shape of animals!

Those bracelets are so flatworld. Nobody wears those anymore.
by Nothin But Nachos Quatro October 16, 2010
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