The Collaborative International Dictionary of English v.0.48:

cooker \cooker\ n.
   an implement for cooking.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

cooker
    n 1: a utensil for cooking

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "cooker":
   Dutch oven, alcohol stove, baker, barbecue, boiler, broiler,
   burner, caliduct, camp stove, chafer, chafing dish, cook stove,
   cookery, element, furnace, gas jet, grill, griller, heater,
   heating duct, infrared cooker, jet, pans, percolator, pilot light,
   roaster, samovar, steam pipe, stove, tewel, toaster, tuyere,
   warmer