How many letters does the top answer for “a city in northern illinois” have?

The most common answer is rockford (8 letters).

Crossword clue: a city in northern illinois

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

rockford 8 letters wn-def

a city in northern Illinois

a city in northern italy 50% similar → ferrara

city in northern cyprus 50% similar → kyrenia, lapathus, salamis

city in northern district 50% similar → beitshean

city in northern province 50% similar → byumbahospital, kasama, makeni

city in northern region 50% similar → mosta, mzuzu, naxxar

city in northern state 50% similar → napata, wadihalfa

city in northern territory 50% similar → darwin, palmerston