oleomargarine (n.)

butter substitute, 1873, from French margarine (see margarin). Invented 1869 by French scientist Hippolyte Mège-Mouries and made in part from edible fats and oils.

The "enterprising merchant" of Paris, who sells Margarine as a substitute for Butter, and does not sell his customers by selling it as Butter, and at Butter's value, has very likely found honesty to be the best policy. That policy might perhaps be adopted with advantage by an enterprising British Cheesemonger. ["Punch," Feb. 21, 1874]