hemosiderin
noun
he·mo·sid·er·in ˌhē-mō-ˈsi-də-rən 
: a yellowish-brown, iron-containing, granular pigment that is found within cells (such as macrophages), is composed chiefly of aggregates of ferritin, and is typically associated with bleeding and the breakdown of red blood cells (as in hemolytic anemia)
Word History
Etymology
borrowed from German Hämosiderin, from hämo- hem- + Greek sídēros "iron" + German -in -in entry 1 — more at sidero-
Note: Term introduced by the German pathologist Ernst Neumann (1834-1918) in "Beiträge zur Kenntniss der pathologischen Pigmente," Archiv für pathologische Anatomie und Physiologie, Band 111 (1888), pp. 25-47.
First Known Use
1888, in the meaning defined above
Medical Definition
hemosiderin
noun
he·mo·sid·er·in
variants or chiefly British haemosiderin
ˌhē-mō-ˈsid-ə-rən
: a yellowish brown granular pigment formed by breakdown of hemoglobin, found in phagocytes and in tissues especially in disturbances of iron metabolism (as in hemochromatosis, hemosiderosis, or some anemias), and composed essentially of colloidal ferric oxide compare ferritin