Neathage, Bottom Breasts Cleavage Girl

Exposure of the underside of the breast, such as below an extremely short crop top, is known as neathage (a blend of underneath and cleavage), Australian cleavage (because of the reference to Australia as down-under), bottom cleavage, reverse cleavage or underboob.
History
In European society, décolletage was often displayed in the dress of the late Middle Ages. This continued through the Victorian period. Corsets that enhance the cleavage were introduced in the mid 16th century. By the late 18th century these cleavage enhancing corsets grew more dramatic in pushing the breasts upwards. It is a feature of the evening gown, leotard, and bikini, among other fashions. In the French Enlightenment, there was a debate as to whether a woman's breasts were merely a sensual enticement or rather a natural gift to be offered from mother to child. In Moissy's play The True Mother, the title character rebukes her husband for treating her as merely an object for his sexual gratification: "Are your senses so gross as to look on these breasts – the respectable treasures of nature – as merely an embellishment, destined to ornament the chest of women?" Nearly a century later, also in France, a man from the provinces who attended a Court ball at the Tuilleries in Paris in 1855 was deeply shocked by the décolleté dresses and is said to have exclaimed in disgust: "I haven't seen anything like that since I was weaned!"