ptosis

noun

1. (countable, uncountable)The prolapse of a bodily organ, especially drooping of the eyelid or the breasts.

   “There were many other factors to be taken into account: Miss West’s age, the type of enlargement, whether the condition was one of pure hypertrophy, the degree of ptosis present, the actual scale of enlargement and, finally, the presence of any pathology in the breast tissue itself.”