Mundelein (mənˈdəlĪn) [key] village (1990 pop. 21,215), Lake co., NW of Chicago, NE Ill.; founded 1835 as Mechanics Grove, inc. 1909. The name was changed in 1926 to honor George Cardinal Mundelein. Its light industries produce a variety of household goods. The Univ. of St. Mary of the Lake/Mundelein Seminary is there.