tonic in WordNet English dictionary

1. used of syllables
   "a tonic syllables carries the main stress in a word"
   tonic  accented 
   
2. imparting vitality and energy
   "the bracing mountain air"
   bracing  brisk  fresh  refreshing  refreshful  tonic 
   
3. employing variations in pitch to distinguish meanings of otherwise similar words
   "Chinese is a tonal language"
   tonic  tonal 
   
4. of or relating to or producing normal tone or tonus in muscles or tissue
   "a tonic reflex"; "tonic muscle contraction"
   tonic 
   
5. relating to or being the keynote of a major or minor scale
   "tonic harmony"
   tonic 
   

1. (music) the first note of a diatonic scale
   tonic  keynote 
   
2. a sweet drink containing carbonated water and flavoring
   "in New England they call sodas tonics"
   pop  soda  soda pop  soda water  tonic 
   
3. lime- or lemon-flavored carbonated water containing quinine
   tonic  tonic water  quinine water 
   
4. a medicine that strengthens and invigorates
   tonic  restorative