Bromide
Definition: a meaningless statement or platitude
Technically, a bromide is a scientific noun, referring to some part of the chemical compoud Bromine.
Historically, a common usage of bromides is as a sedative. It was commonly used as an anesthetic before modern discoveries.
Hence, a “bromide” in speech or writing is something so meaningless or commonplace that it threatens to put someone to sleep.
Why I Looked It Up
In a (negative) review of Kristi Noem’s memoir:
She’s also found of wise bromides that belong stiched on a wall-hanging.