Anelastic is a term often used in physics to describe materials that exhibit time-dependent elastic behavior. Synonyms for anelastic include viscoelastic, which refers to materials that exhibit both viscous and elastic properties, and rheopectic, which describes materials that become more viscous over time when subjected to stress. Another synonym is creep, which refers to the time-dependent deformation of a material under constant stress. Additionally, thixotropic describes materials that become less viscous over time under stress. These terms are useful for scientists and engineers working with materials that must withstand various amounts of stress over time.