The term 'ILL. NEIGHBOR' can be broken down into three crossword solutions: WIS (3 letters), WISC (4 letters), and IND (3 letters). WIS stands for Wisconsin, a state located in the Midwestern United States. WISC is an abbreviation for the University of Wisconsin-Madison, a public research university located in Madison, Wisconsin. Lastly, IND stands for Indiana, a state located in the Midwestern United States that borders Wisconsin to the west. Therefore, the term 'ILL. NEIGHBOR' can be used to refer to the two Midwestern states of Wisconsin and Indiana, which are neighbors to each other.