One who reigns over a state or territory, usually for life and by hereditary right, especially:
A sole and absolute ruler.
A sovereign, such as a king or empress, often with constitutionally limited authority: a constitutional monarch.
One that commands or rules: "I am monarch of all I survey"(William Cowper).
One that surpasses others in power or preeminence: "Mont Blanc is the monarch of the mountains"(Byron).
A monarch butterfly.
[Middle English monarke, from Old French monarque, from Late Latin monarcha, from Greek monarkhos : mono-, mono- + arkhein, to rule.] mo·nar'chal (mə-när'kəl), mo·nar'chic (-kĭk), mo·nar'chi·cal (-kĭ-kəl) adj., mo·nar'chal·ly, mo·nar'chi·cal·ly adv.