tonic
ton·ic / ˈtänik/ • n. 1. a medicinal substance taken to give a feeling of vigor or well-being. ∎ something with an invigorating effect: being needed is a tonic for someone at my age.2. short for tonic water.3. Mus. the first note in a scale that, in conventional harmony, provides the keynote of a piece of music.• adj. 1. giving a feeling of vigor or well-being; invigorating.2. Mus. relating to or denoting the first degree of a scale.3. Phonet. denoting or relating to the syllable within a tone group that has greatest prominence, because it carries the main change of pitch.4. relating to or restoring normal tone to muscles or other organs. ∎ Physiol. relating to, denoting, or producing continuous muscular contraction.DERIVATIVES: ton·i·cal·ly / -ik(ə)lē/ adv.
