senescence
Concise Oxford English Dictionary © 2008 Oxford University Press:
senesce /sɪˈnɛs/
▶verb Biology (of a living organism) deteriorate with age.
– derivatives
senescence noun,
senescent adjective.
senescence noun,
senescent adjective.
– origin C17: from L. senescere, from senex ‘old’.
'senescence' also found in these Oxford entries:

