a serious and sometimes fatal illness characterized by a marked reduction of leucocytes, usually caused by hypersensitivity to certain drugs
agranulocytosis in American English
(eɪˌgrænjuˌloʊsaɪˈtoʊsɪs)
noun
a disorder characterized by a significant decrease of granulocytes in the blood and often resulting in high fever, weakness, and ulceration of the mucous membranes