grandfather paradox

[ grand-fah-ther par-uh-doks, gran- ]

noun

1. (in science fiction) a paradox created by time travel in which a person travels back in time and changes something in their own past or the past of their own timeline, after which the resulting timeline is altered such that the future point from which the time travel began does not exist or is unrecognizable.

Word History and Origins

Origin of grandfather paradox¹

First recorded in 1970–75