The Collaborative International Dictionary of English v.0.48:

Atomizer \At"om*i`zer\ ([a^]t"[u^]m*[imac]`z[~e]r), n.
   One who, or that which, atomizes; esp., an instrument for
   reducing a liquid to spray for disinfecting, cooling, or
   perfuming.
   [1913 Webster]

WordNet (r) 3.0 (2006):

atomizer
    n 1: a dispenser that turns a liquid (such as perfume) into a
         fine mist [syn: atomizer, atomiser, spray, sprayer,
         nebulizer, nebuliser]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "atomizer":
   aerosol, aspergil, aspergillum, censer, clyster,
   concentrate sprayer, douche, enema, evaporator, fountain syringe,
   fumigator, incense burner, incensory, mist concentrate sprayer,
   needle bath, nozzle, odorator, odorizer, parfumoir, perfumer,
   pomander, potpourri, pouncet-box, purse atomizer, retort, sachet,
   scent bag, scent ball, scent bottle, scent box, scenter, shower,
   shower bath, shower head, smelling bottle, sparge, sparger, spray,
   spray can, sprayer, sprinkler, sprinkler head, sprinkling system,
   still, syringe, thurible, vaporizer, vinaigrette, watercart,
   watering can, watering pot