constitutional monarchy
noun [ C ] uk/ˌkɒn.stɪ.tjuː.ʃən.əl ˈmɒn.ə.ki/ us/ˌkɑːn.stɪ.tuː.ʃən.əl ˈmɑː.nɚ.ki/
君主立宪制
a system in which the king or queen's power is severely limited, because they act only on the advice of the politicians who form the government