WordNet (r) 3.0 (2006):
haematocrit n 1: the ratio of the volume occupied by packed red blood cells to the volume of the whole blood as measured by a hematocrit [syn: hematocrit, haematocrit, packed cell volume] 2: a measuring instrument to determine (usually by centrifugation) the relative amounts of corpuscles and plasma in the blood [syn: hematocrit, haematocrit]