Musk

Musk is a class of aromatic substances commonly used as base notes in perfumery. They include glandular secretions from animals such as the musk deer, numerous plants emitting similar fragrances, and artificial substances with similar odors. Musk was a name originally given to a substance with a penetrating odor obtained from a gland of the male musk deer. The substance has been used as a popular perfume fixative since ancient times and is one of the most expensive animal products in the world. The name, originated from Sanskrit muṣká meaning "testicle," has come to encompass a wide variety of substances with somewhat similar odors although many of them are quite different in their chemical structures.