Gaius is a Latinpraenomen, or personal name, and was one of the most common names throughout Roman history. The feminine form is Gaia. The praenomen was used by both patrician and plebeian families, and gave rise to the patronymic gensGavia. The name was regularly abbreviated C., based on the original spelling, Caius, which dates from the period before the letters "C" and "G" were differentiated. Inverted, Ɔ. stood for the feminine, Gaia. Throughout Roman history, Gaius was generally the second-most common praenomen, following only Lucius. Although many prominent families did not use it at all, it was so widely distributed amongst all social classes that Gaius became a generic name for any man, and Gaia for any woman. A familiar Roman wedding ceremony included the words, spoken by the bride, ubi tu Gaius, ego Gaia, to which the bridegroom replied, ubi tu Gaia, ego Gaius. The name survived the collapse of the Western Empire in the fifth century, and continued into modern times.
Origin and meaning
The author of De Praenominibus states that Gaius is derived from the same root as gaudere, "to rejoice". Although Paris and the unidentified authorities whom he consulted probably relied on folk etymology, modern scholars generally concur with this derivation. The original form of the name was probably Gavius, in which form it was also used by the Oscans. However, in Latin it had already lost its medial "v" by the time of the earliest inscriptions. An archaic three-syllable pronunciation given above, in which the "a" and "i" are pronounced separately as, is evidence of the original form. This pronunciation persisted, alongside the later two-syllable form in which "a" and "i" are pronounced together as , throughout the period of the Roman Republic. The existence of the patronymic gens Gavia also indicates the original form of the name, although it could be argued that this family's name was derived from the Oscan praenomen Gavius. But as Gaius and Gavius are apparently based on the same root, this distinction is of limited importance. In the form Cae, this praenomen was also popular amongst the Etruscans, who borrowed many names from both Latin and Oscan.