or chiefly Brit  hae*mo*sid*er*in  n :  a yellowish brown granular pigment formed by breakdown of hemoglobin, found in phagocytes and in tissues esp. in disturbances of iron metabolism (as in hemochromatosis, hemosiderosis, or some anemias), and composed essentially of colloidal ferric oxide - compare FERRITIN  .
 
 
 
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