vegetable oil ve·ge·tab·leoil uncommon noun 1. any of a group of liquid edible fats that are obtained from plants Synonymsvegetable oiloil Related words Broader terms edible fat Narrower terms cooking oilsweet oilcanola oilcoconut oilcorn oilcottonseed oilolive oilpalm oil Parts margarine WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.