petrochemical noun 2adjective 1forms 1 noun2 •Any chemical derived from petroleum.Another is a Bloomberg project we're participating in that looks beyond petrochemicals. — 2023 •Any chemical derived from any of the fossil fuels: petroleum, natural gas, or coal.As the prices of petroleum, natural gas, and coal fluctuate over the years, the petrochemical industry can to some extent switch feedstocks. adjective1 •Of or pertaining to the such compounds, or the industry that produces them. formspetrochemicals