IMPLUVIUM
Etymology
Noun
impluvium (plural impluviums or impluvia)
(architecture) A low basin in the center of a household atrium, into which rainwater flowed down from the roof through the compluvium.
Source: Wiktionary
Im*plu"vi*um, n. Etym: [L., fr. impluere to rain into; pref. im- in +
pluere to rain.] (Arch.)
Definition: 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.
Source: Webster’s Unabridged Dictionary 1913 Edition