Reservoir \Res"er*voir`\ (r[e^]z"[~e]r*vw[^o]r`; 277), n. [F. r['e]servoir, fr. LL. reservatorium. See Reservatory.]

1. 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.

2. (Bot.) A small intercellular space, often containing resin, essential oil, or some other secreted matter.

Receiving reservoir (Water Works), a principal reservoir into which an aqueduct or rising main delivers water, and from which a distributing reservoir draws its supply.

Source: Webster's Revised Unabridged Dictionary (1913)