Tenement is a term usually used to describe a crowded, decaying apartment building. But a tenement may refer to any dwelling that is rented to two or more families or tenants. A tenement can be an old residential building that has been divided to house low-income families at low standards. It can also be a new structure built for many low-income families--each in its own small apartment. An urban district that houses numerous tenements is often called a slum.