Meaning of souvenir sheet

souvenir' sheet"

Pronunciation: [key]
— Philately. Philately.
  1. a single stamp or a pair, block, or set of stamps having the same or different designs commemorating a stamp exhibition or other event and having inscriptions in one or all four margins.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.