Uchronia
The term uchronia refers to a hypothetical or fictional time period of our world, in contrast to altogether-fictional lands or worlds. The concept is similar to alternate history, but uchronic times are not easily defined but are placed mainly in some distant or unspecified point before current times, and they are sometimes reminiscent of a constructed world. Some, however, use uchronia to refer to an alternate history.
The word is a neologism from the word utopia, replacing topos with chronos. It was coined by Charles Renouvier as the title of his 1876 novel Uchronie, esquisse historique apocryphe du développement de la civilisation européenne tel qu'il n'a pas été, tel qu'il aurait pu être.
The term has been applied to Philip K. Dick's The Man in the High Castle and Philip Roth's The Plot Against America.
