WordNet (r) 3.0 (2006):

watering can
    n 1: a container with a handle and a spout with a perforated
         nozzle; used to sprinkle water over plants [syn: watering
         can, watering pot]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "watering can":
   aerosol, aspergil, aspergillum, atomizer, clyster,
   concentrate sprayer, douche, enema, fountain syringe,
   mist concentrate sprayer, needle bath, nozzle, shower, shower bath,
   shower head, sparge, sparger, spray, spray can, sprayer, sprinkler,
   sprinkler head, sprinkling system, syringe, watercart,
   watering pot