Which term is used to describe a material that has different properties in different directions?

The term used to describe a material that exhibits different properties in different directions is anisotropic material. Anisotropic materials have directional dependence, meaning that their mechanical, thermal, or elastic properties can vary based on the orientation of the material. This characteristic can significantly impact how these materials behave under stress, temperature changes, or when subjected to various forces.

In contrast, homogeneous materials have uniform properties in all directions, meaning their behavior is consistent regardless of the direction of applied forces. Composite materials consist of two or more constituent materials and may exhibit anisotropic behavior depending on their composition and structure, but the term itself does not inherently describe directional properties. Elastic materials refer to a material's ability to return to its original shape after deformation and do not specify directional behavior. Thus, the unique property of being directionally dependent is what makes anisotropic material the correct choice in this context.