/ Dictionary / Index H hypertonia: Meaning and Definition of Find definitions for: hy•per•to•ni•a Pronunciation: (hī"pur-tō'nē-u), [key] — n. Pathol. increased rigidity, tension, and spasticity of the muscles. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hypertonia (Thesaurus) hyperthyroidism hypertonic Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language