cturePhonet., Now Rare designating or of sounds characterized by resonance in the head cavities; also, accentedMed., Physiol. of or characterized by tone, or tonusOrigin of tonicClassical Greek tonikos ; from tonos: see tonenoun anything that invigorates or stimulates; specif., a drug, medicine, or other agent for restoring or increasing body tone a hair or scalp dressing a carbonated beverage fla