monarch
n. countablen. a king, queen, or other person who rules a country. They usually get their power because they were born into a royal family.
n. a sovereign head of state, especially a king, queen, or emperor. Often used to describe a hereditary ruler in a constitutional or absolute system.
The monarch addressed the nation on television last night.
Under the new constitution, the monarch remains the head of state but holds very little political power.
The transition from an absolute to a constitutional system significantly altered the role of the monarch, shifting executive authority to an elected parliament while retaining the crown as a symbol of national unity.
From Middle French monarque, from Late Latin monarcha, from Ancient Greek μονάρχης (monárkhēs), variant of μόναρχος (mónarkhos, “sole ruler”), from μόνος (mónos, “only”) + ἀρχός (arkhós, “leader”), equivalent to mono- + -arch. * (butterfly): See monarch butterfly.