ETYM Cf. French fluoride.
A salt of hydrofluoric acid.
Negative ion (Fl-) formed when hydrogen fluoride dissolves in water; compound formed between fluorine and another element in which the fluorine is the more electronegative element (see electronegativity, halide).
In parts of India, the natural level of fluoride in water is 10 parts per million. This causes fluorosis, or chronic fluoride poisoning, mottling teeth and deforming bones.
Compound of fluorine, especially one introduced into public water supply to combat dental decay.