The term "mammillary line" refers to the visible crease that runs horizontally across the chest, just below the breasts. This line is commonly referred to as the "cleavage line" or "cleavage wrinkles" due to its association with the visible separation between the breasts. Additionally, it is sometimes called the "décolletage line", emphasizing the area of exposed skin between the breasts. Other synonyms for mammillary line include "bosom crease" or "breast fold", which describe the physical appearance of the line. These terms are often used in discussions related to fashion, aesthetics, and breast augmentation procedures.