Definitions for gaiusˈgeɪ əs
Random House Webster's College Dictionary
a.d. c110–c180, Roman jurist and writer on civil law.
Caligula, Gaius, Gaius Caesar(noun)
Roman Emperor who succeeded Tiberius and whose uncontrolled passions resulted in manifest insanity; noted for his cruelty and tyranny; was assassinated (12-41)
The Nuttall Encyclopedia
a Roman jurist of the 2nd century, whose "Institutes" served for the basis of Justinian's.