In politics, a figurehead is a person who holds de jure an important (often supremely powerful) title or office yet de facto executes little actual power, most commonly limited by convention rather than law. but in some cases may have little power even by law. The metaphor derives from the carved figurehead at the prow of a sailing ship. Other figureheads are the Emperor of Japan, the King of Sweden, or presidents in some parliamentary republics, such as the President of India, President of Israel, President of Bangladesh, President of Greece, President of Germany, President of Pakistan, and the President of the People's Republic of China (without CPC General Secretary post).
While the authority of a figurehead is in practice generally symbolic or ceremonial, public opinion, respect for the office or the office holder and access to high levels of government can give them significant influence on events. Sometimes a figurehead with reserve powers can be exploited in times of emergency. For example, Indian Prime Minister Indira Gandhi used the figurehead President of India to issue unilateral decrees that allowed her to bypass parliament when it no longer supported her.
During the crisis of the March on Rome in 1922, King Victor Emmanuel III of Italy, though a figurehead, played a key role in handing power to Benito Mussolini. More than 20 years later, the same King Victor Emmanuel III of Italy played a key role in the dismissal of Benito Mussolini in 1943. Since the abolition of monarchy in Italy and the establishment of a republic in 1948, the Italian President assumed most of the ceremonial functions of the previous kings; however, the Italian President retains large powers in appointing a prime minister of his choice when in parliament there's no clear majority, creating a so-called "president's cabinet". For example, the actual (2013) Prime Minister of Italy, Sen Mario Monti, was not elected but appointed by the Italian President (Giorgio Napolitano) as a lifetime-senator and then as Prime Minister of the country.
Conversely, King Juan Carlos I of Spain, also largely considered a figurehead, had in 1981 a key role in defending the newborn Spanish democracy and foiling the attempted coup d'état, known as "23-F".
As a derogatory term
The word can also have more sinister overtones, and refer to a powerlful leader, who should be exercising full authority, who is actually being controlled by a more powerful figure behind the throne.