from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A layer of sand or gravel on the bottom of a reservoir or tank, used to filter water or sewage.
from the GNU version of the Collaborative International Dictionary of English
- n. a pond, the bottom of which is a filter composed of sand gravel.
from The Century Dictionary and Cyclopedia
- n. A pond or tank having a false bottom covered with sand, and serving to filter river- or pond-waters.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. filter consisting of a layer of sand or gravel for filtering water
Sorry, no etymologies found.