Definitions
1.NounA deep, wide defensive ditch, normally filled with water, surrounding a fortified habitation.
2.NounAn aspect of a business which makes it more "defensible" from competitors, because of the nature of its products, services or franchise or for some other reason.
3.NounA circular lowland between a resurgent dome and the walls of the caldera surrounding it.
4.NounA clear ring outside the eyewall of a tropical cyclone.
5.NounA hill or mound.
6.VerbTo surround with a moat.