irrigate

Concise Oxford English Dictionary © 2008 Oxford University Press:
irrigate /ˈɪrɪgeɪt/

▶verb

• 1 supply water to (land or crops) by means of channels.

  ■ (of a river or stream) supply (land) with water.

• 2 Medicine apply a flow of water or medication to (an organ or wound).

– derivatives
irrigable adjective,
irrigation noun,
irrigator noun.

– origin C17: from L. irrigat-, irrigare ‘moisten’.