Parece que é isso...

Heitor, essa definição da wikipedia que vc colocou é para instalações elétricas grandes. Pelo texto entendo que trata-se da malha de terra para placas de circuito impresso (PCB). Então seria o ground plane. Veja:

Printed circuit boards

A ground plane on a printed circuit board (PCB) is a large area or layer of copper foil connected to the circuit's ground point, usually one terminal of the power supply. It serves as the return path for current from many different components.

A ground plane is often made as large as possible, covering most of the area of the PCB which is not occupied by circuit traces. In multilayer PCBs, it is often a separate layer covering the entire board. This serves to make circuit design easier, allowing the designer to ground any component without having to run additional traces; component wire needing grounding is routed directly through a hole in the board to the ground plane on another layer. The large area of copper also conducts the large return currents from many components without significant voltage drops, ensuring that the ground connection of all the components are at the same reference potential.

http://en.wikipedia.org/wiki/Ground_plane

malha de terra => ground grid

ground grid
About 78,600 results

Multipoint ground - Wikipedia, the free encyclopedia
www.en.wikipedia.org/wiki/Multipoint_ground
A ground grid is provided primarily for safety, and the size of the conductors is ... Lightning protection is provided by bonding the multipoint ground grid to one or ...

Ground Grid Systems Software | Uniform & Cost Effective Grid - ETAP
www.etap.com/ground-grid-systems/ground-grid-systems.htm
ETAP Ground Grid Systems module enables engineers to quickly and accurately design and analyze a safe and cost effective ground protection.

Systems Ground Grid - ETAP
www.etap.com/downloads/factsheets/ground-grid-systems.pdf
Protection. Systems. The next generation Ground Grid Systems module enables engineers to quickly and accurately design and analyze ground protection.

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Note added at 12 hrs (2012-09-22 15:54:47 GMT)
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"grounding grid"
About 44,400 results

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Note added at 12 hrs (2012-09-22 15:57:17 GMT)
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Grounding Strategies for Printed Circuit Boards
www.ce-mag.com/ce-mag.com/archive/01/03/0103CE_028.html
Ground Grid (Ground Matrix). A ground grid forms a series of box sections on the PCB. A ground area beneath each integrated circuit (IC) on the component side ...

AN10897 - NXP Semiconductors
www.nxp.com/documents/application_note/AN10897.pdf
– For reduced inductance, the ground grid spacing should be under 13 mm. Ideally, the top and bottom side of the PCB should look like a gro