petroleum       
noun [ U ] uk/pəˈtrəʊ.li.əm/ us/pəˈtroʊ.li.əm/
 石油
a dark, thick oil obtained from under the ground, from which various substances including petrol, paraffin, and diesel oil are produced
 Synonyms: crude oil 
 - More examples
 - Petrol and diesel are produced from petroleum.
 - Products which are petroleum-based are highly inflammable.
 - Petroleum is used to produce fuel for vehicles.
 - 'Vaseline' is the commercial name for petroleum jelly.
 - Petroleum jelly can be used to soothe and prevent nappy rash.