in Roman times, an artificial reservoir used for swimming or as a fish pond. During the Middle Ages a piscina was a pool or tank in which fish were stored by monastic communities, for whose members fish was a staple item of diet.

Although never a calculated feature of gardens, existing ponds or fish stews (tanks) were sometimes later incorporated in decorative schemes. At Monticello, Thomas Jefferson's home near Charlottesville, Va., an original piscina has been restored.

A stone vessel having a drain that leads directly to the ground, located near an altar of a church, and used for disposing of water from ablutions is also known as a piscina.