hematocrit

definition: a measuring instrument to determine (usually by centrifugation) the relative amounts of corpuscles and plasma in the blood
example:
speech part: noun
synonyms: haematocrit
definition: the ratio of the volume occupied by packed red blood cells to the volume of the whole blood as measured by a hematocrit
example:
speech part: noun
synonyms: haematocrit packed cell volume

How hematocrit is being used?