/ Dictionary / Index T tonic spasm: Meaning and Definition of Find definitions for: ton'ic spasm' Pronunciation: [key] — Med. Med. See under spasm (def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tonic sol-fa tonic water Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language