Meaning of PHOTON in English

[pho.ton] n [phot- +

[2]-on] (1916) 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 adj

Merriam-Webster English vocab.      Английский словарь Merriam Webster.