Yes, the Latin name Anicius has been historically rendered and developed into the vernacular as Anizio. [1]

While the standard modern Italian evolution of the Latin Anicius is Anicio, the variant Anizio arose through natural linguistic shifts and historical scribal practices. [1]

The Linguistic Evolution

• Palatalization and Assibilation: In Vulgar Latin and early Romance languages, the Latin "-ci-" sound followed by a vowel underwent palatalization. Depending on the specific regional dialect of Italy (such as those in northeastern Italy or regions with heavy Tuscan/Venetian linguistic blending), this soft "ts" or "ch" sound frequently shifted into a voiced "z" (pronounced as /dz/ or /z/).
• Scribal Alternation: In Medieval and Renaissance Italian texts, the letters "c" and "z" were often used interchangeably to represent dental affricates. Because of this orthographic flexibility, names from the prestigious Anicia gens were frequently written with a "z". [1]

Historical Examples

You can find the name Anizio used explicitly in vernacular historical biographies and translations of prominent Romans from the Anicia family:

• Boethius: The famous 6th-century Roman philosopher, Anicius Manlius Severinus Boethius, is frequently translated into older or regional Italian texts as Anizio Manlio Severino Boezio. For example, scholarly publications and historical volumes (such as those by I. Coppa in 1940) explicitly print his name as "Anizio". [1, 2, 3]
• Emperor Olybrius: The Western Roman Emperor Flavius Anicius Olybrius is occasionally documented in regional vernacular histories and Western European language variants as Flavio Anizio Olibrio. [1]

Modern Vernacular Usage

Today, Anizio (and its variant Anízio) survives as a rare given name and surname in Italy—particularly in the Lazio and Campania regions. Due to Portuguese maritime migration, the name also successfully migrated into the Portuguese vernacular, where Anízio remains a recognized personal name in Portugal and Brazil. [1, 2, 3, 4, 5]

If you are researching a specific historical text or lineage, I can look into regional Italian dialect rules or find specific medieval manuscript citations where this spelling occurs. Would you like to narrow this down to a particular century or region?