Oleo oil n. An oil expressed from certain animal fats (esp. beef suet), the greater portion of the solid fat, or stearin, being left behind. It is mixture of olein, palmitin, and a little stearin.
... afflicted with rickets and other diseases which could be remedied by the administration of the right amount of fat. He combined fresh suet and milk and called the product "oleomargarine." In the United States this product is now made of oleo oil or soft beef fat, neutral lard, cottonseed and other oils, churned with a small quantity of milk, and in the finer grades, cream is sometimes used. A certain proportion of butter is usually added, and the whole worked up with salt as ... — Foods That Will Win The War And How To Cook Them (1918) • C. Houston Goudiss and Alberta M. Goudiss