Auxetic is a word that describes a material that expands in a perpendicular direction when stretched, unlike most materials that contract. Synonyms for auxetic include dilatant, expanding, and dilating. Dilatant is a term used to describe materials that increase in viscosity or thickness when under stress, such as quicksand. Expanding materials refer to those that grow or increase in size when pulled in different directions. Dilating describes the process of becoming wider or spreading out. These synonyms describe materials that exhibit unique properties when subjected to stress or tension and can have a wide range of applications, from protective gear to smart textiles.