Either of two entirely different substances, distilled from coal tar or wood tar.
Coal-tar creosote is a complex mixture of organic compounds, largely hydrocarbon s. It is a cheap water-insoluble wood preservative used for railroad ties, telephone poles, and marine pier pilings and as a disinfectant, fungicide, and biocide. Wood-tar creosote consists mainly of phenol s and related compounds and was once widely used for pharmaceutical purposes.