WordReference Random House Unabridged Dictionary of American English © 2020
(lo̅o̅′mə nl),USA pronunciation [Pharm., Trademark.]WordReference Random House Unabridged Dictionary of American English © 2020
- Drugs, Trademarksa brand of phenobarbital.
(lo̅o̅′mən),USA pronunciation n., pl. -mens, -mi•na
- Opticsthe unit of luminous flux, equal to the luminous flux emitted in a unit solid angle by a point source of one candle intensity. Abbr.: lm
- Anatomythe canal, duct, or cavity of a tubular organ.
- Botany(of a cell) the cavity that the cell walls enclose.
- Neo-Latin, special uses of Latin lūmen (stem lūmin-) light, window
Collins Concise English Dictionary © HarperCollins Publishers::
lumen /ˈluːmɪn/ n ( pl -mens, -mina / -mɪnə/)
Etymology: 19th Century: New Latin, from Latin: light, apertureˈlumenal, ˈluminal adj
- the derived SI unit of luminous flux; the flux emitted in a solid angle of 1 steradian by a point source having a uniform intensity of 1 candela
- a passage, duct, or cavity in a tubular organ
- a cavity within a plant cell enclosed by the cell walls