Meaning of ground plane

ground' plane"

Pronunciation: [key]
  1. (in perspective drawing) the theoretical horizontal plane receding from the picture plane to the horizon, beginning at the level of the base line.
  2. a ground plate or an underground mesh of radial wires connected to a vertical antennathat is grounded in order to provide suitable radiation characteristics.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.