"Generokee" is a slang, derogatory term for a person who either incorrectly believes he or she has -- or knowingly faisely claims to have -- significant Native American ancestry. The word itself is a portmanteau of "generic" and "Cherokee", the latter being frequently claimed as a tribe of ancestry by Caucasians who want to appear more exotic than they actually are.
For instance, white-appearing people who claim to be the descendants of "Indian princesses" but who don't have genealogical documentation to support their claims will often be seen as Generokees, as will people who engage in thoughtless or fetishistic appropriation of Native American culture while simultaneously claiming some vague tribal ancestry.
As another instance, my mother's family always claimed Cherokee descent due to one of their ancestors having the surname Rainwater (which I later found out was an Americanized German family name and not Native American at all). This pretense was useful to them for a couple of reasons. First, it made them feel more innately salt-of-the-Earth American than if they'd had to acknowledge that all their ancestors were Northern European immigrants who mostly all arrived well after the Revolutionary War; that family narrative of inherent Americanness made them feel justified in viewing recent immigrants with scorn. Further, it made them feel immune to accusations of bigotry when they engaged in racist behaviors toward actual Native Americans.
If you attend a performance of Tecumseh! in Chillicothe, OH, you will see a fair number of people in the audience whom Native Americans would likely view as Generokees.
Bill: "Did you hear Earl bragging about how his great-great-grandfather was a Sioux chief?"
Sarah: "More like a Generokee chief!"
Also known as a Pretendian.