noun

• (inorganic chemistry) A binary compound of bromine and some other element or radical.
• (inorganic chemistry) A binary compound of bromine and some other element or radical.
• (inorganic chemistry) The anionic form of a bromine atom.
  "“How fortunate Buddha, Mahomed, and Shakespeare were that their kind relations and doctors did not cure them of their ecstasy and their inspiration,” said Kovrin. “If Mahomed had taken bromide for his nerves, had worked only two hours out of the twenty-four, and had drunk milk, that remarkable man would have left no more trace after him than his dog. […]”"
• (by extension)
  "My adviser at college was a bromide who had not had an original thought in years."