tachyon

/หˆtรฆki.ษ’n/

IPA: /T AA0 CH IY0 AA0 N/

noun
  1. 1

    A hypothetical particle that travels faster than the speed of light.

  2. 2

    A flaw in a physical theory that predicts the existence of tachyons or similar paradoxical results. Compare with ghost.

Source: https://en.wiktionary.org/wiki/tachyon