fluoride

American  

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

noun

Chemistry.

• fluorides
  plural

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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Other Word Forms

Noun Inflected Forms

• fluorides
  plural

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

Explanation

Fluoride is that ingredient in toothpaste that keeps tooth enamel strong and helps prevent cavities. Small amounts of fluoride are also present in tap water and certain foods and beverages. Fluoride is a naturally occurring mineral widely recognized for its oral health benefits. Fluoride is often added to toothpaste and mouthwash to help prevent tooth decay by making the enamel more resistant to acid attacks from bacteria and sugars. That’s why some communities add it to their water supply systems: Regular exposure to fluoride is generally considered important in maintaining oral hygiene. Fluoride is also found in tea, seafood, and some fruits and vegetables. Now that’s toothsome!

Example Sentences

See Examples For:

fluoride fluorides

It also released about 35 percent of the fluorine atoms originally bound within the chemicals, converting them into fluoride salts.

From Science Daily ● Jul. 20, 2026

Fire Department said it detected low-levels of toxic hydrogen fluoride on the second day of the fire, which can be a byproduct of burning lithium-ion batteries.

From Los Angeles Times ● Jun. 30, 2026

“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

When the precursors were treated with fluoride salts, cubene or quadricyclene formed inside the reaction vessel.

From Science Daily ● Jan. 23, 2026

My fluoride theory is pretty much out the window.

From "Linked" by Gordon Korman

The Moffitt research team wanted to develop a more efficient process to create sulfoximines, sulfonimidoyl fluorides and sulfonimidamides.

From Science Daily ● Jan. 22, 2024

The three heaviest noble gases react with fluorine to form fluorides.

From Textbooks ● Feb. 14, 2019

Such wastes as chlorides, chlorates, salts of phosphonic acid, fluorides, and arsenic had been discharged from the Rocky Mountain Arsenal during the years of its operation by the Army Chemical Corps.

From The New Yorker ● Jan. 3, 2017

In the years since, fluorides have been proved to reduce the rate of tooth decay in adults as well as in children.

From New York Times ● Jan. 23, 2012

Chlorides, chlorates, salts of phosphonic acid, fluorides, and arsenic had been discharged from the Rocky Mountain Arsenal into holding ponds during the years of its operation.

From "Silent Spring" by Rachel Carson