Dictionary.net

M. Thenard gave this name to an extractive matter, contained in muscular flesh and in the blood of animals, which he considers of a peculiar nature. It has an agreeable smell and taste, and is found in Bouillons of meat, in the proportion of one part to seven of gelatin. Vauquelin discovered in it some fungi. It is the substance which gives the flavour of meat to soups, and hence its name. It is a mixture of different crystallizable and uncrystallizable principles with empyreumatic products. An Osmazome chocolate, Chocolata cum osmazoma, has been introduced as an analeptic article of diet.

An extraction from meat.