Meaning

noun any of the salts of hydrobromic acid; formerly used as a sedative but now generally replaced by safer drugs

noun a trite or obvious remark

originFrom brom- + -ide. First used in the sense “dull person” by American artist, art critic, poet, author and humorist Gelett Burgess. Figurative sense ("platitude") by extending the medicating sense through the metaphor of pacifying or placating.

Etymology from Wiktionary, CC BY-SA 3.0