Since the airport seems to have delays on the reg, here's some ways to spend that time so you're not bored as gathered from Time Out Chicago
Spa-- Terminal Gateway Spa has 4 locations throughout the airport
Yoga Room--located on the mezzanine level of Terminal 3,
Work Out-- Hilton Health Club is across from terminals 1, 2, and 3
Eat a Great Meal--The Publican Tavern, Summer House Santa Monica are just a few of the amazing restaurants throughout the airport