- a colorless corrosive gas, HF, the anhydride of hydrofluoric acid, used chiefly as a catalyst and in the fluorination of hydrocarbons.
- a colourless poisonous corrosive gas or liquid made by reaction between calcium fluoride and sulphuric acid: used as a fluorinating agent and catalyst. Formula: HF
- an aqueous solution of hydrogen fluoride; hydrofluoric acid
