/ Dictionary / Index P photometer: Meaning and Definition of Find definitions for: pho•tom•e•ter Pronunciation: (fō-tom'i-tur), [key] — n. Optics. an instrument that measures luminous intensity or brightness, luminous flux, light distribution, color, etc., usually by comparing the light emitted by two sources, one source having certain specified standard characteristics. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: photometer (Thesaurus) photomechanical photometry Related Content Daily Word Quiz: pugilist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language