• a medicine that strengthens and invigorates
• (music) the first note of a diaTonic scale
• a sweet drink containing carbonated water and flavoring; "in New England they call sodas Tonics"
• lime- or lemon-flavored carbonated water containing quinine
• imparting vitality and energy; "the bracing mountain air"
• used of syllables; "a Tonic syllables carries the main stress in a word"
• relating to or being the keynote of a major or minor scale; "Tonic harmony"
• employing variations in pitch to distinguish meanings of otherwise similar words; "Chinese is a tonal language"
• of or relating to or producing normal tone or tonus in muscles or tissue; "a Tonic reflex"; "Tonic muscle contraction"

'Tonic' in other languages