fluorine

noun

fluo·​rine ˈflu̇r-ˌēn 

ˈflȯr-

: a nonmetallic gaseous chemical element of the halogen group with atomic number 9 that readily forms compounds with almost all other elements including some noble gases see Chemical Elements Table

Examples of fluorine in a Sentence

Recent Examples on the Web

These materials include aluminum, cobalt, copper, dysprosium, electrical steel, fluorine, gallium, iridium, lithium, magnesium, graphite, neodymium, nickel, platinum, praseodymium, silicon, silicon carbide and terbium. —Sahit Muja, Forbes.com, 3 Sep. 2025

Another focus is the development of sustainable surfactants that avoid fluorine or silicon. —Bojan Stojkovski, Interesting Engineering, 31 Aug. 2025

This lens features the classic dust and moisture-resistant construction with a fluorine coating on the front element, which repels moisture and oil. —Harry Bennett, Space.com, 29 July 2025

Using a type of test known as total fluorine screening, the researchers found the highest presence of intentional PFAS use in period underwear (33 percent of all products sampled) and reusable pads (25 percent of products). —Emily Kay Votruba, EverydayHealth.com, 28 July 2025

Word History

Etymology

French, from New Latin fluor

First Known Use

1813, in the meaning defined above

Rhymes for fluorine

• agin
• alkene
• allene
• ameen
• amin
• amine
• arene
• athene
• baleen
• beeline
• benzene
• between

Kids Definition

fluorine

noun

flu·​o·​rine

ˈflu̇(-ə)r-ˌēn,

-ən

: a nonmetallic element that is normally found alone as a pale yellowish flammable irritating poisonous gas having two atoms per molecule see element

Medical Definition

fluorine

noun

fluo·​rine ˈflu̇(-ə)r-ˌēn  -ən 

: a nonmetallic monovalent halogen element that is normally a pale yellowish flammable irritating toxic gas

—symbol F see Chemical Elements Table