photon

pho·ton

noun \ˈfō-ˌtän\

Definition of PHOTON

1

: a unit of intensity of light at the retina equal to the illumination received per square millimeter of a pupillary area from a surface having a brightness of one candle per square meter

2

: a quantum of electromagnetic radiation

— pho·ton·ic \fō-ˈtä-nik\ adjective

Origin of PHOTON

phot- + ²-on

First Known Use: 1916

Rhymes with PHOTON

aeon, add-on, agon, agone, Akan, Ambon, Amman, anon, Anshan, archon, argon, Argonne, atman, axon, bank on, barchan, baton, big on, Bion, blouson, bon ton, bonbon, boron, boson, bouillon, bring on, build on, bygone, caisson, call on, canton, capon, cast on, catch on, Ceylon, chaconne, Charon, chew on, chiffon, chiton, chrismon, Cimon, cistron, clip-on, codon, come-on, cordon, coupon, crampon, crayon, crepon, cretonne, crouton, Dacron, dead-on, Dear John, doggone, Dogon, Don Juan, exon, fall on, flacon, foregone, form on, Freon, fronton, futon, Garonne, get on, Gibran, gluon, gnomon, go on, guidon, hadron, Hainan, hand on, hands-on, hang on, have on, hazan, head-on, Henan, hereon, high on, hit on, hogan, hold on, Huainan, icon, intron, ion, jargon, Jinan, jomon, kanban, kaon, Kashan, keen on, Khoisan, Kirman, koan, krypton, kurgan, Kurgan, lauan, lepton, let on, lock on, log on, look on, Luzon, macron, Masan, Medan, Memnon, meson, micron, Milan, mod con, moron, mouton, Multan, muon, natron, nekton, neon, nephron, neuron, neutron, ninon, Nippon, nylon, odds-on, Oman, Oran, Orlon, paeon, parton, Pathan, pavane, pecan, peon, Phaëthon, phyton, pick on, pion, piton, plankton, pluton, pompon, prion, proton, Pusan, push on, put-on, pylon, python, racon, radon, rag on, rayon, recon, rhyton, run-on, run on, Saint John, Saipan, salon, San Juan, Schliemann, Schumann, Shaban, shaman, shaitan, Shingon, sign on, sit on, slip-on, snap-on, solon, Solon, soupçon, soutane, stand on, stolon, stuck on, Suwon, sweet on, Taiwan, taipan, take on, tampon, taxon, Teflon, Tehran, teston, thereon, Tian Shan, tisane, torchon, toucan, toyon, trade on, trigon, Tristan, triton, trogon, try on, Tucson, turned-on, turn on, Typhon, tzigane, uhlan, Ulsan, upon, wait on, walk-on, witan, whereon, Wonsan, wonton, work on, Wuhan, xenon, Xi'an, Yukon, Yunnan, zircon

pho·ton

noun \ˈfō-ˌtän\   (Medical Dictionary)

Medical Definition of PHOTON

1

: a unit of intensity of light at the retina equal to the illumination received per square millimeter of a pupillary area from a surface having a brightness of one candle per square meter—called also troland

2

: a quantum of electromagnetic radiation

photon

noun    (Concise Encyclopedia)

Minute energy packet of electromagnetic radiation. In 1900 Max Planck found that heat radiation is emitted and absorbed in distinct units, which he called quanta. In 1905 Albert Einstein explained the photoelectric effect, proposing the existence of discrete energy packets in light. The term photon came into use for these packets in 1926. The energies of photons range from high-energy gamma rays and X rays to low-energy infrared and radio waves, though all travel at the same speed, the speed of light. Photons have no electric charge or rest mass and are the carriers of the electromagnetic field.

Variants of PHOTON

photon or light quantum