A circular lowland between a resurgent dome and the walls of the caldera surrounding it.
A clear ring outside the eyewall of a tropical cyclone.
An 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.
A deep, wide defensive ditch, normally filled with water, surrounding a fortified habitation.
To surround with a moat.
A ridge or berm at a perimeter
The green border of a field, dug up in order to carry the earth onto other land to improve it.
A line of snow left behind by the edge of a snowplow’s blade.
A long snowbank along the side of a road.
A line of leaves etc heaped up by the wind.
A similar streak of seaweed etc on the surface of the sea formed by Langmuir circulation.
A line of gravel left behind by the edge of a grader’s blade.
A row of cut grain or hay allowed to dry in a field.
To arrange (e.g. new-made hay) in lines or windrows.