the GNU version of the Collaborative International Dictionary of English
n. A ditch or moat.
n. See Fossa.
The Century Dictionary and Cyclopedia
n. see foss.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. ditch dug as a fortification and usually filled with water
Word Usage
"Avebury had at one time within a great rampart and a fosse, which is still forty feet deep, a large circle of rough unhewn stones, and within this two circles each containing a smaller concentric circle."