from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a system of watercourses or drains for carrying off excess water
Sorry, no etymologies found.
I was on one of the highest points of the Downs, looking east to the valleys where the uplands slid away towards the Thames, that hadn't been a grand waterway in Alfred's life - time, more a long winding drainage system from the Cotswolds to the North Sea.