Ansonia, a manufacturing village in the town of Derby, New Haven co., Conn., on the E. bank of the Naugatuck river and on the Naugatuck railroad, 9 m. W. N. W. of New Haven; pop. in 1870, 2,749. It was established by Phelps, Dodge and company of New York, and named from Mr. Anson G. Phelps. It has 11 rolling mills, 2 founderies, white lead works, woollen mills, extensive clock, hoop skirt, and other factories, good public water works, a bank, several churches, and many fine residences. The fall in the river at this point affords excellent water power.