Gaius

Latin

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Gaius

For Gāvius, from Proto-Italic *Gāwjos, a derivative of Proto-Indo-European *geh₂w- (“to rejoice”). Cognate with gaudeō, gaudium. Cognate with Etruscan 𐌂𐌀𐌄 (cae).

Gāius m (genitive Gāiī or Gāī, feminine Gāia); second declension

a masculine praenomen, in particular:
1. Gaius (an eminent jurist who lived in the second century A.D.)
2. Caligula, the emperor Gaius Julius Caesar Augustus Germanicus
Qui totus servatus est in Gaiorum et Quintorum laterculis.^source
Which was kept in its entirety on the registers of Gaiuses and Quintuses.

1876, "C" in the Encyclopædia Britannica, 9th ed., Vol. IV, page 616:
The symbol [C] retained its old value [/ɡ/] only when as the initial letter it represented the names Gaius and Gnæus, which, in consequence, are often erroneously written and sounded Caius and Cnæus.

¹Found in older Latin (until the Augustan Age).

“Gaius”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
“Gaius”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.