juvenescence
Concise Oxford English Dictionary © 2008 Oxford University Press:
juvenescence /ˌdʒuːvəˈnɛs(ə)ns/
▶noun formal youth.
– derivatives
juvenescent adjective.
juvenescent adjective.
– origin C19: from L. juvenescent-, juvenescere ‘reach the age of youth’, from juvenis ‘young’.
'juvenescence' also found in these Oxford entries:

