Wiktionary
antiplane
a. (context mechanics English) Being or pertaining to a special class of deformation where the displacements in the body are zero in the plane of interest but non-zero in the direction perpendicular to that plane.
Usage examples of "antiplane".
This tiny group, under half a hundred, only four or five pilots, and an antiplane battery that had already failed to shoot down one of the minesite attack craft, to defend a whole planet?