"instrument used to measure the intensity of light," 1778, from photo- "light" + -meter "device for measuring." Related: Photometric; photometry (1760).
Entries linking to photometer
photo-
word-forming element meaning "light" or "photographic" or "photoelectric," from Greek photo-, combining form of phōs (genitive phōtos) "light" (from PIE root *bha- (1) "to shine").
-meter
word-forming element meaning "device or instrument for measuring;" commonly -ometer, occasionally -imeter; from French -mètre, from Greek metron "a measure," from PIE root *me- (2) "to measure."