erythrocytosis
noun
eryth·ro·cy·to·sis
| \ i-ˌrith-rə-ˌsī-ˈtō-səs
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plural erythrocytoses\ -ˈtō-ˌsēz
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Medical Definition of erythrocytosis
: an increase in the number of circulating red blood cells especially resulting from a known stimulus (as hypoxia) — compare polycythemia