musk / məsk/ • n. 1. a strong-smelling reddish-brown substance that is secreted by the male musk deer for scent-marking and is an important ingredient in perfumery. ∎  a similar secretion of another animal, such as a civit. 2. (also musk plant or musk flower) a plant (genus Mimulus) of the figwort family that was formerly cultivated for its musky perfume.

musk odoriferous substance secreted by the musk-deer. XIV. — late L. muscus — Pers. mušk, perh. — Skr. mu⋅ká — scrotum (the shape of the musk-deer's musk-bag being similar).