he·mat·o·crit 
(hĭ-mătə-krĭt′)
(hĭ-mătə-krĭt′)n.
1. The percentage by volume of packed red blood cells in a given sample of blood after centrifugation.
2. A centrifuge used to determine the volume of blood cells and plasma in a given sample of blood.
[HEMATO- + Greek kritēs, judge (from krīnein, to judge; see krei- in the Appendix of Indo-European roots).]