The flow of a fluid (through a pipe etc.) in a direction opposite to that which is normal or intended.
To flow in the wrong or backward direction.
The process or state of growing worse, or the state of having become worse.
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.
Gradual deterioration, from natural causes, of any class of animals or plants or any particular organ or organs; hereditary degradation of type.
A thing that has degenerated.