massless

/ˈmæsləs/
adjective
  1. Having no mass; not having physical substance or weight.
    • In physics, photons are considered massless particles.
    • The concept of a massless object is hard to imagine in everyday life.
    • Scientists study massless particles to understand the early universe.
Antonyms
What does "massless" mean? | whatsthatwordmean | whatsthatwordmean