Entry 1 sense Webster, 1913 Haematology /(hĕm`ȧ*tŏl"ō̇*jy̆ [or] hē`mȧ-)/ · Haem·a·tol·o·gy · IPA /ˌhiməˈtɑləd͡ʒi/ 01 n. The science which treats of the blood. Same as Hematology. 1. The science which treats of the blood. Same as Hematology. See: Hematology