Synonyms for tonic

lime- or lemon-flavored carbonated water containing quinine (noun)

a sweet drink containing carbonated water and flavoring (noun)

• pop
• soda

(music) the first note of a diatonic scale (noun)

• keynote

a medicine that strengthens and invigorates (noun)

• restorative

employing variations in pitch to distinguish meanings of otherwise similar words (adj)

• tonal

(used of syllables) bearing the principle stress, usually accompanied by a change in pitch (adj)

• accented

imparting vitality and energy (adj)

• bracing
• brisk
• fresh
• refreshing
• refreshful