You can delete any custom entity type you created as long as it is not assigned to a policy. If an entity type is assigned to a policy, you must remove it from the policy before you can delete it. Preinstalled entity types (identified by the lock icon) cannot be deleted.
Expand the Manage section in the left navigation menu.
Click Entity types.
Locate the entity type you want to delete.
Click the ellipses (…) at the end of the row.
Click Delete in the menu that displays.
Select OK when prompted to verify you want to delete the entity type.
If an entity type is assigned to a policy, you will receive a message indicating the policy that contains the entity type. Use the Go to Polices button to view a list of the polices that contain the entity type. You will need to remove the entity type from all the polices before you can delete it.