Meaning of flexagon

flex•a•gon

Pronunciation: (flek'su-gon"), [key]
— n.
  1. a three-dimensional figure having polygonal faces that is constructed from a folded sheet of paper in such a way that different faces are exposed when the figure is flexed along its folds.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.