i cheated! from wikipedia..
""Chicagoland" is an informal name for the Chicago metropolitan area, used primarily by copywriters, advertising agencies, and traffic reporters.[
citation needed] There is no precise definition for the term "Chicagoland," which may be larger than the MSA and include portions of the greater CSA. The
Chicago Tribune, which coined the term, includes the city of Chicago, the rest of
Cook County, eight nearby Illinois counties;
Lake,
McHenry,
DuPage,
Kane,
Kendall,
Grundy,
Will and
Kankakee, and two counties in
Indiana;
Lake and
Porter.
[4] The Illinois Department of Tourism defines Chicagoland as Cook County
without the city of Chicago, and only Lake, DuPage, Kane and Will counties.
[5] The
Chicagoland Chamber of Commerce defines it as all of Cook, and DuPage, Kane, Lake, McHenry and Will counties.
[6]"
although i swear i have driven through a town called chicagoland on hwy 30 a few times and it didnt look like a fun place... but maybe i'm just recalling them using the term chicagoland when i was listening to the radio in that area.