BROMIDE, chemically, a compound of bromine with an ele ment or an organic radical, or a salt of hydrobromic acid, such as sodium bromide. Various bromides are of value in medicine, especially potassium bromide which is extensively used as a car diac and cerebral depressant. From the application of the term bromide in the sense of a nerve sedative has arisen the colloquial meaning of a bromide as a platitude ; a person whose inane con versation bores excessively is called bromidic.