Wiktionary
n. A dark yellow resinous acidic oil obtained as a byproduct during the pulping of pine; it is used in the manufacture of soaps and lubricants
WordNet
n. an oil derived from wood pulp and used in making soaps or lubricants
Wikipedia
Tall oil, also called "liquid rosin" or tallol, is a viscous yellow-black odorous liquid obtained as a by-product of the Kraft process of wood pulp manufacture when pulping mainly coniferous trees. The name originated as an anglicization of the Swedish "tallolja" ("pine oil"). Tall oil is the third largest chemical by-product in a Kraft mill after lignin and hemicellulose; the yield of crude tall oil from the process is in the range of 30 – 50 kg / ton pulp. It may contribute to 1.0 - 1.5% of the mill's revenue if not used internally.
Usage examples of "tall oil".
There is hardly a point from which one cannot see in the middle or farther distance, looming through the faintly bluish haze of the acrid smog, a hill densely studded with tall oil derricks.
It was dark, the only near light was from the windows of a few houses and a tall oil-burning lamp on a street corner half a block away.
I regained consciousness by slow degrees, gradually becoming aware of a vast, dark cavern lit by tall oil torches.
Now he continued up Compton Boulevard past the tall oil derricks, through Compton, through all the silent streets.