I. |ȯ(r)thə|träpik adjective
Etymology: orth- + -tropic
: having the longer axis more or less vertical — compare plagiotropic
• or·tho·trop·i·cal·ly -pə̇k(ə)lē adverb
II. adjective
1. : being, having, or relating to properties (as strength, stiffness, and elasticity) that are symmetric about two or three mutually perpendicular planes
a piece of straight-grained wood is an orthotropic material
2. of a bridge : designed so that the roadway serves as an orthotropic structural member : constructed with a steel-plate deck as an integral part of the support structure