Merriam-Webster Collegiate Dictionary - musk

 noun  Etymology: Middle English ~e, from Middle French musc, from Late Latin muscus, from Late Greek moschos, from Middle Persian *musk-, from Sanskrit mu?ka testicle, from diminutive of mu? mouse; akin to Old English mus mouse  Date: 14th century  1.  a. a substance with a penetrating persistent odor obtained from a sac beneath the abdominal skin of the male ~ deer and used as a perfume fixative; also a similar substance from another animal or a synthetic substitute  b. the odor of ~; also an odor resembling ~ especially in heaviness or persistence  2. any of various plants with ~y odors; especially ~ plant