/ Dictionary / Index A actinometer: Meaning and Definition of Find definitions for: ac•ti•nom•e•ter Pronunciation: (ak"tu-nom'i-tur), [key] — n. a device for measuring intensity of radiation, esp. that of the sun. Cf. actinograph. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: actinometer (Thesaurus) actinology actinomorphic Related Content Daily Word Quiz: hedonist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language