the GNU version of the Collaborative International Dictionary of English
adj. Pertaining to, or designating, the highest oxygen acid, HBrO4, of bromine.
The Century Dictionary and Cyclopedia
Noting an acid, a compound having the formula HBrO4, analogous to perchloric acid, supposed by Kämmerer to be produced by acting on the latter in a dilute state with bromine. Its existence is very doubtful.