Chapra (chäˈprə) [key], city (1991 pop. 136,877), Bihar state, NE India, on the Ghaghara River near its junction with the Ganges. It is a rail and road junction and an agricultural trade center. In the 18th cent. the European factories in the area were destroyed by floods. In the early 20th cent. the city was ravaged by plague. Chapra has four colleges affiliated with Bihar Univ.