WordNet (r) 3.0 (2006):

vegetable oil
    n 1: any of a group of liquid edible fats that are obtained from
         plants [syn: vegetable oil, oil]

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "vegetable oil":
   Macassar oil, absinthe, animal oil, avocado oil, bay oil,
   beechnut oil, camphor, candlenut oil, carapa oil, castor oil,
   cedarwood oil, cerate, clove oil, cocoa butter, copaiba, copra oil,
   corn oil, croton oil, drying oil, edible oil, essential oil, ester,
   eucalyptus oil, fat, fatty oil, fixed oil, flaxseed oil, grease,
   gum spirit, hempseed oil, hydrogenated fat, kekuna oil,
   laurel butter, lemon oil, linseed oil, lipid, mineral oil, nut oil,
   oil, oil of almonds, oleoresin, oleum, olive oil, palm oil,
   palm-kernel oil, peanut oil, perilla oil, pine oil, pine tar,
   pine-tar oil, polyunsaturated fat, poppyseed oil, rape oil,
   ricinus oil, rosin grease, rosin oil, sebum, sesame oil,
   soybean oil, spikenard, tallow, turpentine, unsaturated fat,
   volatile oil, wood oil