Tertius is a Latin-derived masculine given name, most commonly associated with ancient Rome. Its direct translation into English is 'third,' which likely stems from its use as a Roman numeral. Tertius was often used as a cognomen, a third given name in the tria nomina system of ancient Rome. Individuals named Tertius were typically the third son in their families, following the naming convention of the time. The name Tertius has also been incorporated into Christian tradition, with Tertius appearing in the New Testament as the scribe who wrote down the Epistle to the Romans, dictated by the Apostle Paul.
"The name Tertius was quite popular in 1987 with six births recorded that year."