a strong, fuming acid that is a water solution of the gas, or liquid, hydrogen fluoride (HF, HF, HF, or HF, depending on the temperature): it reacts with silicates and is therefore used in etching glass
Origin:
hydro- + fluor(ine) + - IC
See hydrofluoric acid in American Heritage Dictionary 4
noun
A colorless, fuming, corrosive, dangerously poisonous aqueous solution of hydrogen fluoride, HF, used to etch or polish glass, pickle certain metals, and clean masonry.