After leaving the court in 1605, Vrančić moved to Rome, where he entered the Order of St. Paul, the so-called Barnabites. In Rome, Vrančić lived in the house of a Spanish nobleman, John the Baptist of Vives, near Piazza del Popolo square. He met Giovanni Ambrogio Mazent (1565 – 1635), the editor of the collection of technical drawings entitled Codice Atlantico by Leonardo da Vinci (1452-1519). Friendship with the Barnabite Mazent encouraged Vrančić to study machine construction and solve architectural problems.

With the permission of Vrančić, the Czech Benedictine Peter Loderecker, in 1605, used the linguistic material of Dictionarium and prepared the second edition, adding two more languages, Czech and Polish.