From Longman Dictionary of Contemporary Englishphotonpho‧ton /ˈfəʊtɒn $ ˈfoʊtɑːn/ noun [countable] technical HPa unit of energy that carries light and has zero mass
Examples from the Corpus
photon• Consider a photon which is polarised parallel to the optical axis of P, .• But photons are extremely odd particles indeed.• How will you capture photons fast enough to propel the sail at speed and over long distances?• The great advantage of using lower-energy photons rather than X-rays is the greater resolution attainable.• But here things are very different: each individual photon behaves like a wave entirely on its own!• Consider also, this kind of phenomenon affects not just photons, but every particle in every interaction.• How can it be that by allowing the photon an alternative route, we have actually stopped it from traversing either route?• The two photons are like the left and the right eyes of the cat.Origin photon (1900-2000) photo- + -on “particle” (from ion) 