candela |kanˈdēlə; -ˈdelə| (abbr.: cd) noun Physics
the SI unit of luminous intensity. One candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 × 10 12 Hz and has a radiant intensity in that direction of 1/683 watt per steradian.
origin 1950s: from Latin, ‘candle.’
