The Collaborative International Dictionary of English v.0.48:

Broom \Broom\ (br[=oo]m), n. [OE. brom, brome, AS. br[=o]m; akin
   to LG. bram, D. brem, OHG. br[=a]mo broom, thorn?bush, G.
   brombeere blackberry. Cf. Bramble, n.]
   1. (Bot.) A plant having twigs suitable for making brooms to
      sweep with when bound together; esp., the Cytisus
      scoparius of Western Europe, which is a low shrub with
      long, straight, green, angular branches, minute leaves,
      and large yellow flowers.
      [1913 Webster]

            No gypsy cowered o'er fires of furze and broom.
                                                  --Wordsworth.
      [1913 Webster]

   2. An implement for sweeping floors, etc., commonly made of
      the panicles or tops of broom corn, bound together or
      attached to a long wooden handle; -- so called because
      originally made of the twigs of the broom.
      [1913 Webster]

   Butcher's broom, a plant (Ruscus aculeatus) of the Smilax
      family, used by butchers for brooms to sweep their blocks;
      -- called also knee holly. See Cladophyll.

   Dyer's broom, a species of mignonette (Reseda luteola),
      used for dyeing yellow; dyer's weed; dyer's rocket.

   Spanish broom. See under Spanish.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Broom \Broom\, v. t. (Naut.)
   See Bream.
   [1913 Webster] broomcorn

WordNet (r) 3.0 (2006):

broom
    n 1: a cleaning implement for sweeping; bundle of straws or
         twigs attached to a long handle
    2: any of various shrubs of the genera Cytisus or Genista or
       Spartium having long slender branches and racemes of yellow
       flowers
    3: common Old World heath represented by many varieties; low
       evergreen grown widely in the northern hemisphere [syn:
       heather, ling, Scots heather, broom, Calluna
       vulgaris]
    v 1: sweep with a broom or as if with a broom; "Sweep the crumbs
         off the table"; "Sweep under the bed" [syn: sweep,
         broom]
    2: finish with a broom

Moby Thesaurus II by Grady Ward, 1.0:

37 Moby Thesaurus words for "broom":
   autoclave, brush, carpet sweeper, comb, currycomb, dishcloth,
   dishwasher, doormat, duster, dustpan, facecloth, hackle, hairbrush,
   handkerchief, holystone, hose, mop, napkin, pumice stone, rake,
   scraper, scrub brush, scrubber, serviette, sponge, sudarium, swab,
   toothbrush, toothpick, towel, vacuum cleaner, washboard, washer,
   washing machine, whisk, wisp, wringer