cre·o·sote 
(krēə-sōt′)
(krēə-sōt′)n.
1. A colorless to yellowish oily liquid containing phenols and creosols, obtained by the destructive distillation of wood tar, especially from the wood of a beech, and formerly used as an expectorant in treating chronic bronchitis.
2. A yellowish to greenish-brown oily liquid containing phenols and creosols, obtained from coal tar and used as a wood preservative and formerly as a disinfectant. It can cause severe neurological disturbances if inhaled in strong concentrations.
3. A blackish residue formed, as on the inside of a flue, through condensation of volatile compounds released by incomplete combustion of wood or other fuel.
tr.v. cre·o·sot·ed, cre·o·sot·ing, cre·o·sotes
To treat or paint with coal-based creosote.
[German Kreosot : Greek kreas, flesh; see kreuə- in the Appendix of Indo-European roots + Greek sōtēr, preserver (from sōzein, to save; see teuə- in the Appendix of Indo-European roots).]