reservoir
B2Substantiv/US /rˈɛzəvwˌɑr/ RĔZ-əvw-är; UK /rˈɛzəvwˌɑr/ RĔZ-əvw-är/
A place where anything is kept in store; especially, a place where water is collected and kept for use when wanted, as to supply a fountain, a canal, or a city by means of aqueducts, or to drive a mill wheel, or the like.
