Case in point: The useful warnings I found on Native Languages of the Americas. Whether you are Indian, wish you were Indian, or have a Native American character you need to name, be sure to check this site first. For example:
"WEEKO: Some Internet sources claim this word means "pretty" in Dakota or Lakota Sioux. It emphatically does not. It is a slang form of wikoska and it means "venereal disease." I can only hope this 'name' was made up by some writer of Western romance novels who had no idea what it really means."