slum area vs skid row

slum area and skid row both are nouns.

Word	Noun	Adjective	Verb	Adverb
slum area	Yes	No	No	No
skid row	Yes	No	No	No

As nouns, skid row is a hyponym of slum area; that is, skid row is a word with a more specific, narrower meaning than slum area:

slum area: a district of a city marked by poverty and inferior living conditions
skid row: a city district frequented by vagrants and alcoholics and addicts

Other hyponyms of slum area include shantytown.

slum area (noun)	skid row (noun)
a district of a city marked by poverty and inferior living conditions	a city district frequented by vagrants and alcoholics and addicts