Late 18th century; earliest use found in Thomas Jefferson (1743–1826), revolutionary politician and president of the United States of America. From Indian- + -ian.
Definition of Indianian in US English:
Indianian
nounˌɪndɪˈanɪən
Indianan.
Origin
Late 18th century; earliest use found in Thomas Jefferson (1743–1826), revolutionary politician and president of the United States of America. From Indian- + -ian.