Silence Seal
沈黙のお札 / ちんもくのおふだ [chinmoku no ofuda] or 'silence label(s)' in Japanese. The word お札 can variously be translated as 'label', 'seal', or even 'card', among other things, which explains the disrepancy between the translation and the illustration.
Final Fantasy III

Buy: - (sell: ? gil)
Drop: Balloon, Bomb, Fachan, Giant Rat, Grenade, Griffon, Lamia, Lemur, Rock Gargoyle, Tangie, Vulcan
Type: Consumable
Effect: inflicts Silence on single target
Other: was a dummited-out item in the NES version, but was added for real for the DS version
Category: Item