Amastia is a medical condition that refers to the complete absence of breast tissue in women. The term is rarely used outside of medical contexts, but there are several synonyms that can be used to describe this condition. These include breast agenesis, which refers to the failure of breast tissue to develop properly during fetal development, and athelia, which refers to the absence of nipples. Other terms that may be used to describe the absence of breast tissue include breast hypoplasia, which refers to underdevelopment of breast tissue, and breast aplasia, which refers to the complete absence of one or both breasts. Despite their different names and nuances, all of these terms refer to a similar condition and can be used interchangeably in medical contexts.