Pronunciation: (dī"ug-nos'tik),[key] —adj. 1. of, pertaining to, or used in diagnosis.
2. serving to identify or characterize; being a precise indication.
—n. 1. diagnosis (def. 1).
2. a symptom or characteristic of value in diagnosis.
3. Med.a device or substance used for the analysis or detection of diseases or other medical conditions.
4. Computers. a. a message output by a computer diagnosing an error in a computer program, computer system, or component device.
b. a program or subroutine that produces such messages.