The Collaborative International Dictionary of English v.0.48:

Muscovado \Mus`co*va"do\, a. [Corrupted fr. Sp. mascabado; cf.
   Pg. mascavado, F. moscouade, n., formerly also mascovade, It.
   mascavato.]
   Pertaining to, or of the nature of, unrefined or raw sugar,
   obtained from the juice of the sugar cane by evaporating and
   draining off the molasses. Muscovado sugar contains
   impurities which render it dark colored and moist.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Muscovado \Mus`co*va"do\, n.
   Unrefined or raw sugar.
   [1913 Webster]