overdiagnose verb2 •To diagnose something more often than it actually occurs.Health experts deny claims that they overdiagnose mental health conditions. •To diagnose as a clinical case what is truly a subclinical case.Her GP incorrectly referred her to a pulmonologist, overdiagnosing what was clearly a case of subclinical, mild allergy. formsoverdiagnosed · overdiagnosing · overdiagnoses