Definition
To do something erroneously means doing it based on incorrect information or reasoning. It is more formal than 'mistakenly' and suggests a deeper flaw in the information used. It contrasts with doing something deliberately and correctly. For example, you might erroneously believe that a certain diet is healthy, based on false information. It implies a misunderstanding of facts or principles. Erroneously is like relying on a Wikipedia article without checking its sources.