Definition of tachyon in English:

tachyon

noun

Physics
  • A hypothetical particle that travels faster than light.

    • ‘The biggest problem with bosonic string theory (aside from the lack of fermions) is that the lowest energy state was a tachyon, or a particle mode with negative mass squared.’
    • ‘The existence of tachyons is allowed by the equations of Einstein's special theory of relativity.’
    • ‘That brings me to the next interesting point - one way to view the momentum of tachyons is to consider that they have imaginary mass.’
    • ‘Small subatomic particles such as photons, particles of light, and hypothetical particles called tachyons seem to have no problem reaching light speed.’

Origin

1960s: from tachy- swift + -on.

Pronunciation:

tachyon

/ˈtakēˌän/