[ ton-ik ]
See synonyms for tonic on
  1. a medicine that invigorates or strengthens: a tonic of sulphur and molasses.

  2. anything invigorating physically, mentally, or morally: His cheerful greeting was a real tonic.

  1. Music. the first degree of the scale; the keynote.

  2. Chiefly Eastern New England. soda pop.

  3. Phonetics. a tonic syllable or accent.

  1. pertaining to, maintaining, increasing, or restoring the tone or health of the body or an organ, as a medicine.

  2. invigorating physically, mentally, or morally.

  1. Physiology, Pathology.

    • pertaining to tension, as of the muscles.

    • marked by continued muscular tension: a tonic spasm.

  2. using differences in tone or pitch to distinguish between words that are otherwise phonemically identical: a tonic language.

  3. pertaining to tone or accent in speech.

  4. Phonetics. (of a syllable) bearing the principal stress or accent, usually accompanied by a change in pitch.

  5. Music.

    • of or relating to a tone or tones.

    • pertaining to or founded on the keynote, or first tone, of a musical scale: a tonic chord.

Origin of tonic

First recorded in 1640–50, tonic is from the Greek word tonikós pertaining to stretching or tones. See tone, -ic

regional variation note For tonic

5. See soda pop.

Other words for tonic

Other words from tonic

  • ton·i·cal·ly, adverb
  • an·ti·ton·ic, adjective, noun
  • non·ton·ic, adjective
  • pre·ton·ic, noun, adjective

Other definitions for -tonic (2 of 2)


  1. a combining form occurring in adjectives that correspond to nouns ending in -tonia:catatonic.

Origin of -tonic

see origin at tonic Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use tonic in a sentence

  • The vast "morning-room" of the Monumental Club (pre-eminent among clubs for its architecture) was on the whole tonically chilly.

    The Pretty Lady | Arnold E. Bennett
  • It is too proud, too austere, too true, and too tonically cruel to appeal to mandarins.

    Books and Persons | Arnold Bennett

British Dictionary definitions for tonic


/ (ˈtɒnɪk) /

  1. a medicinal preparation intended to improve and strengthen the functioning of the body or increase the feeling of wellbeing

  2. anything that enlivens or strengthens: his speech was a tonic to the audience

  1. Also called: tonic water a mineral water, usually carbonated and containing quinine and often mixed with gin or other alcoholic drinks

  2. music

    • the first degree of a major or minor scale and the tonal centre of a piece composed in a particular key

    • a key or chord based on this

  3. a stressed syllable in a word

  1. serving to enliven and invigorate: a tonic wine

  2. of or relating to a tone or tones

  1. music of or relating to the first degree of a major or minor scale

  2. of or denoting the general effect of colour and light and shade in a picture

  3. physiol of, relating to, characterized by, or affecting normal muscular or bodily tone: a tonic spasm

  4. of or relating to stress or the main stress in a word

  5. denoting a tone language

Origin of tonic

C17: from New Latin tonicus, from Greek tonikos concerning tone, from tonos tone

Derived forms of tonic

  • tonically, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012