from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An instrument for measuring a property of light, especially luminous intensity or flux.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of several instruments used to measure various aspects of the intensity of light.
- v. To measure some aspect of light (from a star) using a photometer.
from the GNU version of the Collaborative International Dictionary of English
- n. An instrument for measuring the intensity of light, or, more especially, for comparing the relative intensities of different lights, or their relative illuminating power.
from The Century Dictionary and Cyclopedia
- n. An instrument used to measure the intensity of light, specifically to compare the relative ! intensities of the light emitted from different sources.
- n. In photography, a device for determining the proper length of time for exposure. See actinometer.
- n. An instrument for determining the length of time proper for photographic exposures.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. photographic equipment that measures the intensity of light
- n. measuring instrument for measuring the luminous intensity of a source by comparing it (visually or photoelectrically) with a standard source
photo- + -meter (Wiktionary)