Entry 1 sense Webster, 1913 Fluoride /flo͝or'-īdˌ/ · Flu·or·ide · IPA /ˈflʊɚˌaɪd/ 01 n. A binary compound of fluorine with another element or radical. 1. A binary compound of fluorine with another element or radical.(Chem.) Phrases & compounds Calcium fluoride — fluorite, CaF2. See Fluorite.