reservoir
‘a storehouse, a place where something is kept safe’
Lexical development traced from the Tamil root:
E. resebiler, reservoi, res'vore, rizzyboiler, reservoire < F. réservoir ‘storehouse’ < O.F. reserver ‘set aside, withhold’ < Lat. reservare ‘keep back, save up; retain, preserve’ <re- ‘back’ + servare ‘to keep, save, preserve, protect’ < zuhv < ser-< Tamil iṟai