Normal deformation is a term used in material science and engineering to describe the deformation of a material, such as stretching or compression, that occurs perpendicular to the surface of the material. There are several synonyms for the term "normal deformation" that are commonly used in the field. These include axial deformation, longitudinal strain, normal strain, and linear strain. Each of these terms refers to the same basic concept of deformation that occurs in a direction perpendicular to the surface of the material. Understanding these synonyms is important in order to effectively communicate and analyze data related to material deformation.