eosinophilia Syllabification: (e·o·sin·o·phil·i·a)Pronunciation: /ˌēəˌsinəˈfilēə/Definition of eosinophilia noun Medicine an increase in the number of eosinophils in the blood, occurring in response to some allergens, drugs, and parasites, and in some types of leukemia. eosinophilia in other Oxford dictionaries Definition of eosinophilia in the British & World English dictionary