What is the meaning for tonic?

Tonic:

1. (adjective) Relating to or denoting the predominant pitch or key of a musical composition.

Example: "Each chapter ends emphatically with a tonic chord, which reinforces the sense of resolution."

2. (noun) A tonic substance, such as a medicine, that invigorates or restores strength.

Example: "The doctor prescribed a tonic to help the patient recover from surgery."

3. (noun) A refreshing drink, typically carbonated and containing caffeine.

Example: "I ordered a tonic water with a slice of lemon."

4. (adjective) Relating to the tone of a muscle, especially the state of normal tension or contraction.

Example: "The therapist worked on strengthening the tonic muscles in the patient's back."

5. (noun) A speech sound that is produced with the vocal cords vibrating regularly, such as a vowel sound.

Example: "In linguistics, a tonic syllable is one that carries the main stress in a word."

6. (adjective) Relating to or denoting the initial accent or stress in a word or phrase.

Example: "In certain languages, tonic stress falls on the first syllable of every word."

The context in which the term "tonic" is used will determine its specific meaning.