1. a thick, dark liquid found underground that is used to make gasoline, oil, and other products

Examples

• The country’s economy depends heavily on petroleum exports.
• Petroleum is refined into gasoline at processing plants.
• Many everyday products are made from petroleum, including plastics and cosmetics.
• The petroleum industry employs thousands of workers worldwide.
• Scientists are developing alternatives to petroleum-based fuels.
• The petroleum reserves in this region are estimated to last fifty years.