1 definition found waukegan - U.S. Gazetteer (1990) : Waukegan, IL (city, FIPS 79293) Location: 42.37090 N, 87.86800 W Population (1990): 69392 (25800 housing units) Area: 57.4 sq km (land), 0.2 sq km (water) Zip code(s): 60087