Definition of gaius:
(N) :
(fl. AD 130–180) a Roman jurist.
(N) :
Gaius, sometimes spelled Caius, was a common Latin praenomen; see Gaius (praenomen).
(N) :
Gaius, feminine Gaia, is a Latin praenomen, or personal name, and was one of the most common names throughout Roman history.
(N) :
the Greek spelling for the male Roman name Caius, a figure in the New Testament of the Bible.
(N) :
a genus of large mygalomorph spiders in the family Idiopidae.