The first lady of the United States is the hostess of the White House.The position is traditionally filled by the wife of the president of the United States, but, on occasion, the title has been applied to women who were not presidents' wives, such as when the president was a bachelor or widower, or when the wife of the president was unable to fulfill the duties of the first lady. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.