First lady is an unofficial title usually used for the wife, and occasionally used for the daughter or other female relative, of a non-monarchical head of state or chief executive. The term is also used to describe a woman seen to be at the top of her profession or art. The title has also been used for the wife of a head of government who is not also head of state. It has also been used to refer to the wives of the leaders of administrative divisions within a country. From Wikipedia
