A racial slur for Native Americans that essentially means a native that has 'red' skin, and is 'white' on the inside. That broken down means a 'red' indian (Native American) that acts white (Acts white).

This term is usally given to Native Americans that do not speak with a 'rez' accent and/or grew up in a city. (As oppose to growing up on a reserve).
This term is usually used amongst Native Americans to insult other Native Americans.