Hydracid

noun

1. In chem., a halogen; an acid which does not contain oxygen.
2. An acid containing hydrogen; -- sometimes applied to distinguish acids like hydrochloric, hydrofluoric, and the like, which contain no oxygen, from the oxygen acids or oxacids. See acid.
3. An acid that does not contain any oxygen as opposed to an oxyacid; they are all binary compounds of hydrogen and a halogen or pseudohalogen.