Your Aunt Eleanor, who's lived in six different countries and speaks four languages fluently, might be described as cosmopolitan, or comfortable and familiar with different cultures and people.
People who are cosmopolitan have an air of glamour surrounding them, a sense that they've seen a lot of the world and are sophisticated and at ease with all different kinds of people. Places can also be described as cosmopolitan, meaning "diverse," or bustling with lots of people of varying nationalities. Any way you use it, cosmopolitan implies a sophistication, which might explain why both a well-known alcoholic cocktail and a famous women's magazine are both named after the word cosmopolitan.
