Source : Webster's Revised Unabridged Dictionary (1913)

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.