Chappaqua (chuh-PAH-guh), upper-income residential village (1990 pop. 6,400), Westchester co., SE N.Y., in N.Y. city suburban area, 5 mi/8 km E of Ossining; 41°09'N 73°45'W. Mfg. (photographic equip. and supplies). Originally a Quaker community; later estate area. Horace Greeley lived here.