1. The study of symptoms.

2. Distinguishing; indicating the nature of a disease.

3. The symptom by which a disease is known or distinguished from others.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• diagnsotic,
• diagnositics,
• diagonostic,
• diagonistic,
• dignoctic,
• diagnastic,
• diagostics,
• diagnost,
• diagnoistic,
• diagonstic,
• diagnotic,
• deagnostic,
• diognostic,
• diasnostic,
• disgnostic,
• daignostic,
• diagnostical,
• digonostic,
• diagnostis,
• diangostic

• diagnostician,
• digenesis,
• diagnostics,
• diagnosis,
• diagnose,
• diogenes,
• diagnosable,
• diagnosing,
• diggins,
• diggings,
• digangi.

The adjective form of the word "diagnostic" is "diagnostic".

The plural of the "diagnostic" can be the "diagnostics".

The singular of the "diagnostic" can be the "diagnostic".