/ Dictionary / Index P pyrheliometer: Meaning and Definition of Find definitions for: pyr•he•li•om•e•ter Pronunciation: (pīr"hē-lē-om'i-tur, pir"-), [key] — n. Astrophysics. an instrument for measuring the total intensity of the sun's energy radiation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pyrexia Pyribenzamine Related Content Daily Word Quiz: simian Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language