Agranulocytosis

Agranulocytosis is a medical condition where there are very few granulocytes (a kind of white blood cell) in the blood. It is a type of severe and dangerous leukopenia (a condition of very low number of white blood cells). If the agranulocytosis is because of a lack of neutrophils (called neutropenia), it is especially bad.
The word agranulocytosis comes from the Greek "a-", meaning "without", the word "granulocyte", referring to a type of blood cell with granules in the cytoplasm, and "-osis", meaning "abnormal condition".