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a mark left by the shod or unshod foot, as in earth or sand.

an impression of the sole of a person's foot, especially one taken for purposes of identification.

Informal.��the track of a tire, especially on wet pavement.

a unique set of characteristics, actions, etc., that leave a trace and serve as a means of identification.

the area affected by an increase in the level of sound or noise, as that generated by an airplane.

Telecommunications.��the area of the earth's surface within which a communications satellite's signals can be received.

Aerospace.��the area within which it is predicted that a spacecraft or its debris will land.

the surface space of a desk or tabletop occupied by a piece of equipment, especially a computer or other electronic device.

the surface area occupied by any structure, device, etc..

the impact that humans have on the environment, especially in the utilization of natural resources.

any impact or effect, or its scope.

Also called ecological footprint.��the amount of biologically productive land and ocean area required to sustain the resource consumption and waste production of an individual, population, or human activity: measured in global acres or hectares.

Computers.��the amount of memory or disk space required by a program.