Source : Webster's Revised Unabridged Dictionary (1913)

Myosin \My"o*sin\, n. [Gr. ?, a muscle.] (Physiol. Chem.)
   An albuminous body present in dead muscle, being formed in
   the process of coagulation which takes place in rigor mortis;
   the clot formed in the coagulation of muscle plasma. See
   {Muscle plasma}, under {Plasma}.

   Note: Myosin belongs to the group of globulins. It is
         insoluble in water, but soluble in dilute solution of
         salt, and is especially characterized by being
         completely precipitated by saturation of its solutions
         with salt.

Source : WordNet®

myosin
     n : the commonest protein in muscle; a globulin that combines
         with actin to form actomyosin