di·ag·nose 
(dīəg-nōs′, -nōz′)
(dīəg-nōs′, -nōz′)v. di·ag·nosed, di·ag·nos·ing, di·ag·nos·es
v.tr.
1. To distinguish or identify (a disease, for example) by diagnosis.
2. To identify (a person) as having a particular disease or condition by means of a diagnosis.
3. To analyze the nature or cause of: diagnose the reasons for an economic downturn.
v.intr.
To make a diagnosis.
[Back-formation from DIAGNOSIS.]
di′ag·nosa·ble adj.