1 definition found cainsville - U.S. Gazetteer (1990) : Cainsville, MO (city, FIPS 10342) Location: 40.44007 N, 93.77447 W Population (1990): 387 (238 housing units) Area: 3.6 sq km (land), 0.0 sq km (water) Zip code(s): 64632