bone oil

from The Century Dictionary.

• noun Fatty matter, of liquid consistence at common atmospheric temperature, extracted from bones by heating them with water or by the use of solvents: used in soap-making.
• noun A fetid, tarry liquid obtained in the dry distillation of bone. See Dippel's oil, under oil.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the liquid portion of bone fat; used as a lubricant and in leather manufacture
• noun dark-colored ill-smelling oil obtained by carbonizing bone; used especially in sheep dips and in denaturing alcohol