The Collaborative International Dictionary of English v.0.48:

Bromide \Bro"mide\, n.
   1. (Chem.) A compound of bromine with a positive radical.
      [1913 Webster]

   2. A person who is conventional and commonplace in his habits
      of thought and conversation. [Slang]
      [Webster 1913 Suppl.]

            The bromide conforms to everything sanctioned by the
            majority, and may be depended upon to be trite,
            banal, and arbitrary.                 --Gelett
                                                  Burgess.
      [Webster 1913 Suppl.]

   3. a conventional or trite saying; -- often used in the
      phrase "old bromide".
      [PJC] Bromide paper

U.S. Gazetteer (1990):

Bromide, OK (town, FIPS 9150)
  Location: 34.41782 N, 96.49429 W
  Population (1990): 162 (89 housing units)
  Area: 1.7 sq km (land), 0.0 sq km (water)

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "bromide":
   abstraction, banality, chestnut, cliche, commonplace,
   commonplace expression, corn, familiar tune, general idea,
   generalization, generalized proposition, glittering generality,
   hackneyed expression, hackneyed saying, lieu commun,
   locus communis, old joke, old saw, old song, old story, platitude,
   prosaicism, prosaism, prose, reiteration, retold story,
   rubber stamp, shibboleth, stereotyped saying, sweeping statement,
   tag, tired cliche, trite saying, triticism, truism,
   twice-told tale