The Collaborative International Dictionary of English v.0.48:

Hydrobromic \Hy`dro*bro"mic\, a. [Hydro-, 2 + bromic.] (Chem.)
   Composed of hydrogen and bromine; as, hydrobromic acid.
   [1913 Webster]

   Hydrobromic acid (Chem.), a colorless, pungent, corrosive
      gas, HBr, usually collected as a solution in water. It
      resembles hydrochloric acid, but is weaker and less
      stable. Called also hydrogen bromide.
      [1913 Webster]

WordNet (r) 3.0 (2006):

hydrogen bromide
    n 1: a colorless gas that yields hydrobromic acid in solution
         with water