Definition of Fluorine 1. A nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite Noun Synonyms for word "fluorine" Semanticaly linked words with "fluorine" Hyponims for word "fluorine" has derived form fluor etymology flox etymology fluorinelike etymology nonfluorine etymology organofluorine etymology radiofluorine etymology fluorin etymology فلورين etymologically related fluor etymologically related fluoric etymologically related fluoro- is derived from fluo- is derived from fluor- is derived from fluorian is derived from fluoride is derived from fluorinate is derived from fluorination is derived from fluorine dating is derived from fluorine method is derived from fluorine oxide is derived from fluorine test is derived from fluorine-18 is derived from fluorine-19 is derived from fluorines is derived from fluoro-