drainage

n. 1. A draining; a gradual flowing off of any liquid; also, that which flows out of a drain. [ 1913 Webster ]

2. The mode in which the waters of a country pass off by its streams and rivers. [ 1913 Webster ]

3. (Engin.) The system of drains and their operation, by which superfluous water is removed from towns, railway beds, mines, and other works. [ 1913 Webster ]

4. Area or district drained; as, the drainage of the Po, the Thames, etc. Latham. [ 1913 Webster ]

5. (Surg.) The act, process, or means of drawing off the pus or fluids from a wound, abscess, etc. [ 1913 Webster ]

Drainage tube (Surg.), a tube introduced into a wound, etc., to draw off the discharges. [ 1913 Webster ]