CURTIS: From the Latin for "court" and Old French for "courteous." Relatives: Curt, Curtys. Namesakes: Curtis Le May, Curtis Sliwa, Curt Flood.
CUYLER: Irish for "chapel." Very nice.
CYNTHIA: From the Greek for "moon." Traditional and melodic. Relatives: Cindie, Cyndi, Cindy, Cinta, Cintia. Namesakes: Cynthia Gregory, Cyndi Lauper.
CYRIL: From the Greek for "lordly." This ninth-century saint catholicized Russia and invented its alphabet to boot. Relatives: Cyrilla, Cyra, Kryil. Namesakes: Cyril Ritchard, Cyril Connolly, Cyra MacFadden.
CYRUS: Persian for "the sun." Cyrus the Great was the founder of the Persian empire. Relative: Cy. Namesakes: Cyrus Vance, Cy Young.