a : an act of giving up sovereign power or high office
The desire of King Edward VIII to marry divorced U.S. socialite Wallis Simpson led to the king's abdication in 1936, an event that also brought Harry, his father Prince Charles and his brother, Prince William, into the line of succession.— Martha Ross From the advent of Alexander the Great, in 332 B.C., to the abdication of King Farouk, in 1952, the country was ruled without interruption by non-Egyptians.— Milton Viorst
b : an act of abandoning or discarding a right, responsibility, etc.
//an abdication of authority The militants took the liberties of Europe as a sign of moral and political abdication.— Fouad Ajami When the majority throws up its hands because the problems are too tough, that's simply an abdication of responsibility.— Michael S. Serrill