Diagnosis: 1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV.
The word diagnosis comes directly from the Greek, but the meaning has been changed. To the Greeks a diagnosis meant specifically a "discrimination, a distinguishing, or a discerning between two possibilities." Today, in medicine that corresponds more closely to a differential diagnosis.