tardyon

/ˈtɑrdiˌɑn/
noun
  1. A particle that travels slower than the speed of light, as opposed to a tachyon.
    • In physics, a tardyon is any particle with mass that cannot reach light speed.
    • The theory distinguishes between tachyons and tardyons based on their velocity.
    • All ordinary matter is made of tardyons, which move at sublight speeds.
Antonyms
What does "tardyon" mean? | whatsthatwordmean | whatsthatwordmean