/ Dictionary / Index T tonometer: Meaning and Definition of Find definitions for: to•nom•e•ter Pronunciation: (tō-nom'i-tur), [key] — n. an instrument for measuring the frequencies of tones, as a tuning fork or a graduated set of tuning forks. any of various physiological instruments for measuring intraocular pressure or blood pressure. an instrument for measuring vapor pressure. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: tonometer (Thesaurus) tono- tonoplast Related Content Daily Word Quiz: hale Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language