1) A neighbourhood where someone who doesn't care is a neighbourhood is 'bad' would live if they wanted to live as cheaply as possible
2) A business neighbourhood (where one might rent office space) that's cheap but not dangerous
3) A place where a travelling church might put up their tent
Googling has only brought up articles aimed for tourists (i.e. bad neighbourhoods to avoid at night, cheap neighbourhoods to stay in, etc.) and real estate pages that aren't always exactly truthful, so I'm looking for the viewpoint of someone who actually knows Washington DC.