Meaning of glide plane

glide' plane"

Pronunciation: [key]
— Crystall. Crystall.
  1. a symmetry element of a space group such that a reflection of the lattice with respect to the plane and a translation of the lattice parallel to the plane bring the lattice back to its original position.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.