urban sprawl vs conurbation

urban sprawl and conurbation both are nouns.

Word	Noun	Adjective	Verb	Adverb
urban sprawl	Yes	No	No	No
conurbation	Yes	No	No	No

As nouns, urban sprawl and conurbation are synonyms defined as:

urban sprawl and conurbation: an aggregation or continuous network of urban communities

Other synonyms of urban sprawl include sprawl.

urban sprawl (noun)	conurbation (noun)
an aggregation or continuous network of urban communities	an aggregation or continuous network of urban communities