senescent

adjective

se·​nes·​cent si-ˈne-sᵊnt 

: relating to, characterized by, or associated with the state of being old or the process of aging : marked by or undergoing senescence

senescent foliage

The "sandwich generation"—caught between adolescent children and senescent parents …

—The Economist

… researchers have opened up a novel approach to combating the effects of aging with the discovery that a special category of cells, known as senescent cells, are bad actors that promote the aging of the tissues.

—Nicholas Wade

Word History

Etymology

borrowed from Latin senēscent-, senēscens, present participle of senēscere "to grow old, age, deteriorate, slacken off, be in decline," from sen-, senex "old, aged, old man" + -ēsc-, suffix of inchoative verbs — more at senior entry 2

First Known Use

1656, in the meaning defined above

Medical Definition

senescent

adjective

se·​nes·​cent si-ˈnes-ᵊnt 

: relating to, characterized by, undergoing, or associated with senescence

Senescent cells secrete a variety of factors but scientists still do not fully understand the role senescent cells play in many physiological processes …

—Science

During ageing, molecular chaperones such as heat-shock proteins are thought to combat stress-related senescent dysfunction.

—Marc Tatar et al., Nature