— thaumatropical /thaw'meuh trop"i keuhl/ , adj.
/thaw"meuh trohp'/ , n.
a card with different pictures on opposite sides, as a horse on one side and a rider on the other, which appear as if combined when the card is twirled rapidly, thus illustrating the persistence of visual impressions.
[ 1820-30; THAUMA(TO)- + -TROPE ]