Final answer:
The traditional reference to the President's wife is 'First Lady', which has been commonly used since the early 19th century.
Step-by-step explanation:
In the United States, the traditional reference to the President's wife is 'First Lady'. The term 'First Lady' is not a formal position or title, but it has been commonly used since the early 19th century to refer to the President's spouse. The First Lady often takes on various ceremonial and public roles but is not an elected or official government position.
Learn more about Traditional reference to the President's wife