1. identifying a disease or medical condition by examining symptoms and test results
Usage: medical context
2. identifying the cause or nature of a problem or fault
Usage: general problem-solving context

Examples

• The doctor is diagnosing the patient’s symptoms.
• She spent hours diagnosing the computer problem.
• Diagnosing the engine trouble required special equipment.
• The specialist is diagnosing a rare condition.
• He’s good at diagnosing what’s wrong with machines.
• Diagnosing the issue took longer than expected.