solar still

Definition

Military

  • noun an emergency method of producing water in the desert. A pit is dug in the sand and a container placed at the bottom. The pit is then covered with some plastic sheeting which is secured at the sides by heaped sand and weighted in the centre by a small stone, thereby forming an inverted cone. Droplets of water form through condensation on the underside of the sheet and trickle down into the container.
http://www.dictionarycentral.com/definition/solar-still.html