Lookups spiked on September 18, 2014.
As Scotland voted whether or not to remain part of the United Kingdom, sovereignty was a word used in many discussions about the reasons and ramifications of the historic referendum.
Sovereignty means "a country's independent authority and the right to govern itself" or "autonomy." It comes from sovereign, itself from the French word that means "king or queen" and ultimately comes from the Latin word that means "over" or "above."
The other word most looked-up during the referendum was federalism, showing that many people were comparing systems of government.