/ Dictionary / Index M myotonia: Meaning and Definition of Find definitions for: my•o•to•ni•a Pronunciation: (mī"u-tō'nē-u), [key] — n. Pathol. tonic muscle spasm or muscular rigidity. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: myotonia (Thesaurus) myotomy Myra Related Content Daily Word Quiz: soporific Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language