Someone from the States. An American. "Support the Troops" bumber stickers, Red+White+Blue t-shirts, Texas belt buckles and slow Southern drawl are dead give aways although in many cases it can be difficult to determine.
1. An American (mostly to non-Americans)
2. A resident of the Eastern U.S.
3. A delinquent or thug (in Japan based on their stereotypes of Americans and mostly comes up in manga or anime
4. A baseball team
1. Barack Obama is a Yankee
2. I live in Ohio; who the hell is a yankee here?
3. Oga Tatsumi from Beelzebub is a yankee.
4. The Yankees are a baseball team.