Oleo is a butterlike spread made from vegetable oils, such as soybean or cottonseed oil. It was invented in the late 19th century as an alternative to butter and lard, and is still widely used today. Oleo is a shortened form of the word oleomargarine, which is derived from the Latin words for oil and margarine. Oleo is a popular choice for baking, cooking, and spreading on toast and sandwiches.