Chicago County is a county located in the U.S. state of Illinois. It is the most populous county in the state and the second-most populous county in the United States. The county seat is Chicago, the largest city in Illinois and the third-largest city in the United States. The county's population is estimated to be over 5 million people. The county is named after the city of Chicago, which is derived from a French rendering of the Native American word shikaakwa, meaning 'wild onion' or 'wild garlic'. The answer to the crossword puzzle is LAHTI, which is a city in Finland.