tonic

of or relating to or producing normal tone or tonus in muscles or tissue

employing variations in pitch to distinguish meanings of otherwise similar words

used of syllables

Of or relating to tones or sounds; specifically (Phon.), applied to, or distingshing, a speech sound made with tone unmixed and undimmed by obstruction, such sounds, namely, the vowels and diphthongs, being so called by Dr. James Rush (1833) " from their forming the purest and most plastic material of intonation."

Characterized by continuous muscular contraction; as, tonic convulsions.

relating to or being the keynote of a major or minor scale

imparting vitality and energy

lime- or lemon-flavored carbonated water containing quinine

a sweet drink containing carbonated water and flavoring

(music) the first note of a diatonic scale

a medicine that strengthens and invigorates

A tonic element or letter; a vowel or a diphthong.