1920s. From Nassau, capital city of the Bahamas (named in the 1690s after Nassau, the family name of King William III of England) + -ian, on the pattern of Latinized forms of proper names ending in -w.
Definition of Nassauvian in US English:
Nassauvian
(also Nassavian)
nounnəˈsɔːvɪən
A native or inhabitant of Nassau.
adjectivenəˈsɔːvɪən
Of or relating to Nassau or its inhabitants.
Origin
1920s. From Nassau, capital city of the Bahamas (named in the 1690s after Nassau, the family name of King William III of England) + -ian, on the pattern of Latinized forms of proper names ending in -w.