WordNet (r) 3.0 (2006):

fuel oil
    n 1: a petroleum product used for fuel [syn: fuel oil,
         heating oil]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "fuel oil":
   Barbados tar, anthracene oil, asphalt-base oil, benzine, coal oil,
   creosote, furnace oil, gas oil, jet fuel, kerosene, lamp oil,
   mineral oil, mineral seal oil, mineral sperm oil, mineral spirits,
   naphthalene, naphthene-base oil, paraffin, petrolatum, petroleum,
   petroleum benzine, road oil, saturating oil, shale naphtha,
   stove oil, technical oil