Catholicon (trilingual dictionary)

The Catholicon (from Greek Καθολικόν 'universal') is a 15th-century dictionary written in Breton, French, and Latin. It is the first Breton dictionary and also the first French dictionary. It contains six thousand entries and was compiled in 1464 by Jehan Lagadeuc, a man from Plougonven who was probably a priest. It was first printed in 1499 in Tréguier; its early date classifies it as an incunable.

The work takes its name from an earlier dictionary, the Latin Catholicon of John of Genoa. The Breton/French/Latin Catholicon is referred to by some historians as the Catholicon Armoricum (in reference to Armorica, a name for the region of Brittany in Latin) in order to distinguish it from other documents with similar names.