Definition of fluoride in US English:



  • 1A compound of fluorine with another element or group, especially a salt of the anion F⁻ or an organic compound with fluorine bonded to an alkyl group.

    • ‘Many elements form fluorides, however, that cannot be labeled covalent or ionic; these halides exhibit the characteristics of polymeric compounds.’
    • ‘Highly substituted alkyl fluorides, perfluoroalkanes, are now used as artificial blood substitutes because of their oxygen transporting properties.’
    • ‘What Sanpaolesi had aimed to do was to consolidate the deteriorated surface of the marble by forming a layer of calcium, zinc and magnesium fluorides and silica gel on the marble surface.’
    • ‘Aluminum is derived in a process that produces air pollutants (e.g., particulates and gaseous fluorides, sulfur dioxide, particulate matter).’
    • ‘Fluxes containing fluorides, chlorides, silica, and borax provide both covering and cleaning, along with the ability to dissolve and collect these objectionable oxide skins.’
    1. 1.1 Sodium fluoride or another fluorine-containing salt added to water supplies or toothpaste in order to reduce tooth decay.
      • ‘A ‘yes’ vote would allow health authorities to make water companies add fluoride to supplies in areas where it is supported.’
      • ‘Both dentists and scientists agree adding fluoride to the water supply is a safe, effective way to help protect teeth, especially young teeth.’
      • ‘Humberside Area Health Authority was to investigate the possibility of introducing fluoride into all water supplies in the county.’
      • ‘Request local water company to supply water with optimum fluoride level.’
      • ‘However, in the mid-1990s, it began to question the wisdom of putting fluoride in the water supply.’
      • ‘A study of 25 popular brands of bottled water found that they were unlikely to contain enough fluoride to protect children's teeth.’
      • ‘The only way to discover whether people wanted fluoride in their water supplies was to hold mini referendums on the issue, he claimed.’
      • ‘AN MP claims the government's backing for putting fluoride in water supplies could be a recipe for murder - with a cup of tea.’
      • ‘Children with fissure sealants still need to brush their teeth with fluoride toothpaste.’
      • ‘Authority members backed the plan but after months of talks Yorkshire Water decided against adding fluoride to supplies.’
      • ‘The Minister for Health is dosing our tap water with chemical fluoride to supposedly give us better teeth.’
      • ‘Peers voted in favour of smoothing the way for water companies to put fluoride in their supplies when the Bill was debated in the Lords during the summer.’
      • ‘Use fluoride toothpaste as fluoride makes teeth stronger and more resistant to acid attacks.’
      • ‘Lancaster City Council heard that water companies could be forced to add fluoride to drinking supplies under moves to prevent tooth decay.’
      • ‘The undersigned strongly support the introduction fluoride into the water supply at the earliest possible opportunity.’
      • ‘There is overwhelming evidence that fluoride can substantially reduce tooth decay.’
      • ‘You may have heard that the addition of fluoride to the water supply is dangerous and damaging.’
      • ‘Some weeks ago we learned that a vote in Parliament had found two of our members in favour of adding fluoride to our water supply and one against.’
      • ‘Like all the other dentists, Lester had learnt in dental school that fluoride reduces tooth decay.’
      • ‘The company is capable of adding fluoride to water supplies, but does not want to have to make the decision whether to or not.’


Early 19th century: from fluorine + -ide.