(1):
(n.) A medicine that increases the strength, and gives vigor of action to the system.
(2):
(n.) A tonic element or letter; a vowel or a diphthong.
(3):
(a.) Increasing strength, or the tone of the animal system; obviating the effects of debility, and restoring healthy functions.
(4):
(a.) 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."
(5):
(a.) Of or pertaining to tension; increasing tension; hence, increasing strength; as, tonic power.
(6):
(n.) The key tone, or first tone of any scale.
(7):
(a.) Characterized by continuous muscular contraction; as, tonic convulsions.