fluoride

American  

[floor-ahyd, flawr-, flohr-] / ˈflʊər aɪd, ˈflɔr-, ˈfloʊr- /

noun

Chemistry.

1. a salt of hydrofluoric acid consisting of two elements, one of which is fluorine, as sodium fluoride, NaF.

2. a compound containing fluorine, as methyl fluoride, CH 3 F.

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fluoride British  

/ ˈflʊəˌraɪd /

noun

1. any salt of hydrofluoric acid, containing the fluoride ion, F ^–

2. any compound containing fluorine, such as methyl fluoride

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fluoride Scientific  

/ flr′īd′ /

1. A compound containing fluorine and another element or radical. Fluorine combines readily with nearly all the other elements, except the noble gases, to form fluorides. In some countries, fluoride is added to the drinking water as a preventive measure against tooth decay.

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fluoride Cultural  

1. Any of a number of naturally occurring compounds of the element fluorine. Fluorides have been found to be effective in preventing tooth decay and are routinely added to drinking water in most jurisdictions.

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Etymology

Origin of fluoride

First recorded in 1820–30; fluor- + -ide ( def. )

Compare meaning

How does fluoride compare to similar and commonly confused words? Explore the most common comparisons:

• fluorine vs. fluoride

Example Sentences

“However, this is still not likely as there was at least some sodium fluoride which would help preserve the sample.”

From Los Angeles Times • Mar. 19, 2026

The Health Secretary has also used his bully pulpit to attack products he views as toxins, including pesticides and fluoride in water.

From The Wall Street Journal • Jan. 7, 2026

With its ability to mimic natural enamel formation and strengthen teeth without fluoride, this new gel could redefine modern dentistry.

From Science Daily • Nov. 6, 2025

"As long as your toothpaste has fluoride, it doesn't make much difference," he says, adding that he tends to buy whatever is cheaper or on offer.

From BBC • Nov. 2, 2025

My fluoride theory is pretty much out the window.

From "Linked" by Gordon Korman