Entry 1 sense Webster, 1913 Haemacytometer /(-sī̇*tŏm"ē̇*tẽr)/ · Haem·a·cy·tom·e·ter · IPA 01 n. An apparatus for determining the number of corpuscles in a given quantity of blood. 1. An apparatus for determining the number of corpuscles in a given quantity of blood.(Physiol.)