Why is the ninth month called September?
late 14c., from Old French musc (13c.) and directly from Late Latin muscus, from Late Greek moskhos, from Persian mushk, from Sanskrit muska-s "testicle," from mus "mouse" (so called, presumably, for resemblance; see muscle). The deer gland was thought to resemble a scrotum. German has moschos, from a Medieval Latin form of the Late Greek word. Spanish has almizcle, from Arabic al misk "the musk," from Persian. Applied to various plants and animals of similar smell (e.g. musk-ox, 1744).
substance obtained from the male musk deer and having a penetrating, persistent odour. It is used in the highest grades of perfume because of its odour characteristics, ability to remain in evidence for long periods of time, and ability to act as a fixative. Its quality varies according to the season and the age of the animal from which it is obtained. In India and parts of the Far East, aphrodisiac, stimulant, and antispasmodic effects have been attributed to musk.