Slum

Slum (pronounced sluhm)

(1) A densely populated, run-down, squalid part of a city, now usually on the outskirts, inhabited by poor people (often used in the plural).

(2) Any squalid, run-down place, especially if used for human habitation.

(3) As slumming it, (1) to visit slums, especially from curiosity or (2), to visit or frequent a place, group, or amusement spot considered to be low in social status or (3), to use goods or services of lesser quality or cheaper than those to which one is accustomed.

(4) Slang for a shabbily dressed person, essentially the noun form of those slumming it (in sense of (3) above) and can be used (“the slums” or “those slums”) as a collective noun for groups of the poorly dressed (now rare).

1825 (noun) & 1884 (verb): A truncation of back slum (dirty back alley of a city, street of poor or low people (1825)), it was initially a slang or cant word meaning "room" and most especially "back room” (1812).  Slumscape, a use drawn from landscape to describe depressed urban housing was first noted in 1947 but never became a popular form although slum-lord (1899), from slum-landlord (1885) was in common use until well into the twentieth century, the use in England diminishing after housing and hygiene regulations began to impose standards improving the condition of rented housing.  Slum is of unknown origin, though there is support from some etymologists for the theory of the imperfect echoic, possibly from a foreign accent.  The most common related form now is used most often in the phrase “slumming it”, an expression indicating (sometimes voluntary) use of some service or product lower in standard than that to which one is accustomed.  The other related forms, slummy, slummily and slumminess are rare probably to the point of being archaic.

Gladstone.

The word first enjoyed popular use as a verb because it was popular in Victorian novels set in London’s East End, the negative association gained from the meaning "to visit slums for disreputable purposes or in search of vice" (1860).  The first modification of the verb form seems to date from 1884 in the sense of "visit slums of a city", especially as a diversion or amusement for the middle-class, often under guise of philanthropy.  Tempting though it is because of the timing, there’s nothing to suggest an etymological connection with the habit of William Ewart Gladstone (1809–1898; variously the UK's chancellor of the exchequer or prime minister 1852-1894) of visiting slums, sometimes after midnight, for his "rescue work": meeting prostitutes on the street, recording their names in his little black book so that he might secure their salvation by arranging worthy and gainful employment.  Sometimes he would take them home for tea and readings from scripture.  Late in life, sensing perhaps the end was nigh, he clarified his role in a "Declaration" executed in his own hand on 7 December 1896.  Embossed with an embargo it was be unsealed only after his death, Gladstone wrote, "I desire to record my solemn declaration and assurance, as in the sight of God and before His Judgement Seat, that at no period of my life have I been guilty of the act which is known as that of infidelity to the marriage bed."  There’s some commendably Clintoneque precision there.

Slumming it: Lindsay Lohan with former special friend, Samantha Ronson, NYC subway, 2008.