American Indian people or things belong to or come from one of the native peoples of America.
[mainly British]
An American Indian is someone who is American Indian.
regional note: in AM, use Indian, Native American
American Indian in British English
noun
1.
a member of any of the indigenous peoples of North, Central, or South America, esp those of North America
adjective
2. Also: Amerindian
of or relating to any of these peoples, their languages, or their cultures
▶ USAGE The term American Indian is still acceptable and is used by indigenous people themselves. However, the mostwidely accepted phrase in general use is Native American
American Indian in American English
a member of any of the indigenous peoples of the Americas, esp. of North America south of the Arctic; Amerindian
originally named Indian by early explorers of the New World, who believed they had reached S Asia