orthotropic Syllabification: (or·tho·trop·ic)Pronunciation: /ˌôrTHəˈtrōpik, -ˈträp-/Definition of orthotropic adjective 1 Botany (of a shoot, stem, or axis) growing vertically. 2 Engineering (of a material) having elastic properties in two or three planes perpendicular to each other. orthotropic in other Oxford dictionaries Definition of orthotropic in the British & World English dictionary