fluoride
noun /ˈflɔːraɪd/, /ˈflʊəraɪd/
/ˈflɔːraɪd/, /ˈflʊraɪd/
- a chemical containing fluorine that protects teeth from decay (= damage from natural causes or lack of care) and is often added to toothpaste and sometimes to drinking waterTopics Physics and chemistryc2Word Originearly 19th cent.: from fluorine + -ide.