The Collaborative International Dictionary of English v.0.48:

Brooch \Brooch\ (br[=o]ch; 277), n. [See Broach, n.]
   1. An ornament, in various forms, with a tongue, pin, or loop
      for attaching it to a garment; now worn at the breast by
      women; a breastpin. Formerly worn by men on the hat.
      [1913 Webster]

            Honor 's a good brooch to wear in a man's hat. --B.
                                                  Jonson.
      [1913 Webster]

   2. (Paint.) A painting all of one color, as a sepia painting,
      or an India painting.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Brooch \Brooch\, v. t. [imp. & p. p. Brooched (br[=o]cht).]
   To adorn as with a brooch. [R.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

brooch
    n 1: a decorative pin worn by women [syn: brooch, broach,
         breastpin]
    v 1: fasten with or as if with a brooch [syn: brooch, clasp]

Moby Thesaurus II by Grady Ward, 1.0:

37 Moby Thesaurus words for "brooch":
   anklet, armlet, bangle, beads, bijou, bracelet, breastpin, broach,
   chain, chaplet, charm, chatelaine, circle, clasp, clip, coronet,
   crown, diadem, earring, fastening, fob, gem, jewel, locket,
   necklace, nose ring, pin, precious stone, rhinestone, ring,
   stickpin, stone, tiara, torque, wampum, wristband, wristlet