degeneration

IPA: dɪdʒɛnɝˈeɪʃʌn

(uncountable, countable) The process or state of growing worse, or the state of having become worse.
(uncountable) That condition of a tissue or an organ in which its vitality has become either diminished or perverted; a substitution of a lower for a higher form of structure.
(uncountable) Gradual deterioration, from natural causes, of any class of animals or plants or any particular organ or organs; hereditary degradation of type.
(countable) A thing that has degenerated.

Examples of "degeneration" in Sentences

Macular degeneration is a disease that gradually destroys sharp, central vision.
Age-related macular degeneration is the leading cause of vision loss in adults older than 50.
Macular degeneration is the leading cause of vision loss in my age group, and my vision is practically gone.
The application of the term degeneration may be, and should be, it seems to me, limited to the signs, whether physical or mental, which indicate an obviously downward tendency.
Nordau all but copyrighted the term degeneration, the title of his best-selling book.43 Degeneration for Nordau designated irrational and romantic ideas in culture, a decay of reason.
He perceived that many forms had been subjected to what he calls degeneration, or, as we say, modification, and that the progress from the simple to the complex was by no means direct.
It's long been known that repeated head blows can cause brain degeneration in boxers, he said, but "the degree to which it appears to be happening in other contact sports ... is the new thing."
I. was an institution endowed with important functions. (_b_) I. is found to be unusually prevalent among savages and primitive races, whereas the term degeneration is generally limited to higher civilization (I. Bloch).