cre·o·sote / ˈkrēəˌsōt/ • n. (also creosote oil) a dark brown oil distilled from coal tar and used as a wood preservative. It contains a number of phenols, cresols, and other organic compounds. ∎ a colorless, pungent, oily liquid, containing creosol and other compounds, distilled from wood tar and used as an antiseptic.• v. [tr.] treat (wood) with creosote.