\Im*plu"vi*um\, n. [L., fr. impluere to rain into;
pref. im- in + pluere to rain.] (Arch.)
In Roman dwellings, a cistern or tank, set in the atrium or
peristyle to recieve the water from the roof, by means of the
compluvium; generally made ornamental with flowers and works
of art around its birm.