Irrigation

is the artificial application of water to the soil usually for assisting in growing crops. In crop production it is mainly used to replace missing rainfall in periods of drought, but also to protect plants against frost.[1] Additionally irrigation helps to suppress weed growing in rice fields.[2] In contrast, agriculture that relies only on direct rainfall is sometimes referred to as dryland farming or as rain fed farming. It is often studied together with drainage, which is the natural or artificial removal of surface and sub-surface water from a given area.

Irrigation is also a term used in the Medical/Dental fields and refers to flushing and washing out anything with water or another liquid.