Dictionary:

bromidic

  (brō-mĭd'ĭk)

Stale, trite, or commonplace through overuse; clichéd: bromidic gags in sitcoms.

adjective

Without freshness or appeal because of overuse: banal, clichéd, commonplace, corny, hackneyed, musty, overused, overworked, platitudinal, platitudinous, shopworn, stale, stereotyped, stereotypic, stereotypical, threadbare, timeworn, tired, trite, warmed-over, well-worn, worn-out. See excite/bore/interest, usual/unusual.

The adjective has 2 meanings:

Meaning #1: given to uttering bromides
  Pertains to noun: bromide (meaning #2)

Meaning #2: dull and tiresome but with pretensions of significance or originality
  Synonyms: corny, platitudinal, platitudinous