reservoir
res.er.voir \'rez-*(r)v-.wa:r, -*(r)v-.(w)o.r, -*r-.vo.i\ n [F re`servoir, fr. MF, fr. reserver] 1: a place where something is kept in store : as 1a: an artificial lake where water is collected and kept in quantity for us e 1b: a part of an apparatus in which a liquid is held 2: an extra supply : RESERVE 3: an organism in which a parasite that is pathogenic for some other specie s lives and multiplies without damaging its host; also : a noneconomic organism within which a pathogen of economic or medical importance flourishes
 Webster's English Dictionary
 Webster's English Dictionary