Metareality

Metareality was a form of reality pertaining to time and space, the metafabric of the space-time continuum.

The Seventh Doctor explained that the power represented by the Pythia's death-curse created shock waves and patterns within the metafabric of the space-time continuum. Cursing the entire population of Gallifrey to perpetual sterility with no children ever, the procreative impulse of an entire species couldn't just dissipate and would've had to go somewhere, the Doctor elaborating that it must have been channelled by the curse. Kadiatu Lethbridge-Stewart dreamed about the Pythia, seeing the curse leave a bow wave in the metareality of time and space. (PROSE: Transit)

The Grey Man built Cathedral as a metacultural engine to introduce randomness into the universe before the existence of Gabriel and Tanith. The Mandelbrot Set, deciding they were no longer conducive to their programme, explained that their presence accelerated generation of entropy, drawing forth "the time of levelling and the end of all thing," which the Set predicted would happen several meta-centuries earlier than expected. (PROSE: Falls the Shadow)