noun / verb
creosote
KREE-uh-soht/ˈkriːəsəʊt/
A tar-derived substance resulting from the heating or burning of organic material.
Creosote gives the wooden railroad tie a dark, oily sheen.

Etymology
The name means “flesh preserver”: creosote was used as an antiseptic and to preserve meat. Its name thus records a particular use of its preservative properties.
In context
Creosote buildup is another area where mesquite outperforms what you might expect from such a dense, smoky wood.
More examples
- Burning wood leaves creosote inside the chimney.
- A thick buildup of creosote can catch fire.
- Workers creosote the fence posts to protect them from rot.
Forms
creosote · creosotes · creosoted · creosoting