Enter a clue or pattern or both:
The Clue
Massless particle (6 letter answer)
The Answer
PHOTON
Tags
Notes
The answer PHOTON is so rare that it appears less than once every 2900 puzzles.
Related Clues
Bit of illumination
Unit of light intensity
Definition
PHOTON as a noun:
1. a quantum of electromagnetic radiation; an elementary particle that is its own antiparticle