The enumeration date is as you surmised the actual date the info was recorded. The official enumeration date was 1 June 1850, all questions were to refer to that date. So she probably died sometime between 1 June and Sept 11. Don.
Definition of plague. 1  an annoyance; those children are a damn plague. 2  any large scale calamity (especially when thought to be sent by God) 3  a swarm of insects that attack plants; a plague of grasshoppers. 4  any epidemic disease with a high death rate.
a serious (sometimes fatal) infection of rodents caused by Yersinia pestis and accidentally transmitted to humans by the bite of a flea that has bitten an infected animal. plague, pestilence, pest (noun).used absolutely, usually capitalized: The Pest) The pestilent disease Plague, caused by the virulent bacterium Yersinia pestis and mostly known by its variant form bubonic plague. plague (Noun). An epidemic or pandemic caused by any pestilence, but specifically by the above disease.