Monarch
Part of speech: noun
Definition: The ruler of an absolute monarchy or the head of state of a constitutional monarchy. A migratory butterfly, Danaus plexippus, found in North America. See w:en:Monarch butterfly.
Example sentence: There is no necessity to separate the monarch from the mob; all authority is equally bad.
Sovereign
Part of speech: adjective
Definition: Exercising power of rule.Exceptional in quality.Having supreme, ultimate power.
Part of speech: noun
Definition: A monarch; the ruler of a country.One who is not a subject to a ruler or nation.A gold coin minted by the United Kingdom.A very large champagne bottle with the capacity of about 25 liters, equivalent to 33⅓ standard bottles.
Example sentence: The only part of the conduct of any one, for which he is amenable to society, is that which concerns others. In the part which merely concerns himself, his independence is, of right, absolute. Over himself, over his own body and mind, the individual is sovereign.