IPA: /ˌdɛdʒəˈneɪʃən/
KK: /dɪˌdʒɛnəˈreɪʃən/
The process or state of losing function, quality, or structure in an organism, tissue, or system, often due to disease, aging, or injury.
The degeneration of the muscle tissue was evident in the patient's condition.
Degeneration is formed from "de-" (meaning down or away) and "generare" (meaning to produce or generate). The word describes a process of moving down or away from a previous state of quality or function, indicating a decline or deterioration.
Think of 'going down' ('de-') from a state of 'production' or 'generation' ('generare') — that's why degeneration means a decline in quality or function.