An extremist right-wing secret society in the US.
The Ku Klux Klan was originally founded in the southern states after the Civil War to oppose social change and black emancipation by using violence and terrorism. Although disbanded twice, it re-emerged in the 1950s and 1960s and continues at a local level. Members disguise themselves in white robes and hoods and often use a burning cross as a symbol of their organization
Perhaps from Greek kuklos ‘circle’ and clan.