1. n. [Geophysics]
Transverse isotropy, polar anisotropy, axial anisotropy and cross anisotropy are synonymous terms referring to the particular directional character of materials in which properties have the same values in all directions parallel to planes of isotropy and different values perpendicular to or crossing the planes of isotropy; this perpendicular direction is an axis of rotational symmetry.
Alternate Form: TI
See: axis of rotational symmetry, vertical transverse isotropy, horizontal transverse isotropy