Sebastianus

Sebastianus is a Latin masculine given name and epithet meaning "of Sebastian" or "belonging to Sebastian." In Latin texts it appears as a gendered form of the personal name Sebastian and as an adjectival designation for things associated with a person named Sebastian. The name is attested in Late Antiquity and throughout the medieval period, and it has influenced various European forms, including Sebastiano in Italian, Sebastián in Spanish, and Sebastião in Portuguese.

The Latin Sebastianus derives from the Greek Sebastianos, which in turn comes from sebastos meaning venerable, august. The -inus suffix yields a typical Latin adjectival/nomen form used to indicate origin or affiliation.

The most famous bearer of the name in Christian tradition is Saint Sebastian. In Latin hagiography he is Sanctus Sebastianus, a martyr traditionally said to have served in the Roman army and to have died during the Diocletianic persecutions. He is commonly depicted tied to a post and shot with arrows, a motif that became a widespread symbol in medieval art. His cult spread across Western Europe, and he is regarded as a patron of archers, soldiers, and, by some traditions, athletes. His feast day is observed on January 20 in the Western church.

Outside hagiography, Sebastianus appears chiefly as a Latinized form in scholarship and as a source-language equivalent for Sebastianic names in historical documents. In modern usage the form Sebastianus survives mainly in Latin contexts or as a historical or literary epithet; the name persists globally in variants such as Sebastian, Sebastián, Sebastião, and Sebastiano.