Ripening
Part of speech: noun
Definition: The process of becoming ripe.
Part of speech: verb
Definition: To grow ripe; to become mature (said of grain, fruit, flowers etc.)
Aging
Part of speech: verb
Definition: To cause to grow old; to impart the characteristics of age to.
Part of speech: noun
Definition: The process of becoming older or more mature.Allowing something to become older.The deliberate act of making something (such as an antique) appear older than it is.Becoming senescent; accumulating damage to macromolecules, cells, tissues and organs with the passage of time
Part of speech: adjective
Definition: Becoming elderly.
Example sentence: Some calamities - the 1929 stock market crash, Pearl Harbor, 9/11 - have come like summer lightning, as bolts from the blue. The looming crisis of America's Ponzi entitlement structure is different. Driven by the demographics of an aging population, its causes, timing and scope are known.