1) Area which collects rainfall 2) Construction 3) Structure 
• (n.) A surface of ground on which water may be caught and collected into a reservoir.
The area drained by various sized watercourses including dolines.
The area contributing surface water flow to a point on a drainage or river system; can be divided into sub-catchments.
Area of ground around path where water collects in the form of bogs, surface water, springs, streams; affects path drainage.
(kach´ment) the catching or collecting of water. catchment area.
(1) The catching or collecting of water, especially rainfall. (2) A reservoir or other basin for catching water. (3) The water thus caught.
A drainage basin, or the area drained by a particular river system. Adjacent drainage basins are separated by watersheds. In North America, the term watershed refers to the entire drainage basin, and the height of land between basins referred to as a divide.
Area which collects rainfall.
Catch'ment noun A surface of ground on which water may be caught and collected into a reservoir. 
[n] - a structure in which water is collected
something that catches rainfall.
noun a structure in which water is collected
An area that catches water.