Chappaqua is a proper noun referring to a town in New York. It is pronounced with three syllables, stressing the second: cha-PAH-qua, and commonly realized as /tʃəˈpæk.wə/ in American speech. The name combines a first element similar to 'chap' and a final 'qua' sound, and is often used in regional contexts or discussions about New York suburbs.
Full pronunciation guide