transcription, транскрипция: [ dī-ˈäp-tər, ˈdī-ˌäp- ]
noun
Etymology: diopter (an optical instrument), from Middle French dioptre, from Latin dioptra, from Greek, from dia- + opsesthai to be going to see — more at optic
Date: circa 1864
: a unit of measurement of the refractive power of lenses equal to the reciprocal of the focal length in meters