The Proto-Indo-European word *hₐóyus
Word *hₐóyus
Meaning vital force, life, age of vigour
See also Proto-Indo-European: *hₐyeu- ‘young’
Proto-Indo-European: *hₐyuhₓ-n̥-k̂ós ‘youth’
Synonyms *h₂eiw-, *wéihₓ(e)s-

Comments
Mallory J.P. and Adams D. (2006)

Other words that might be of interest
*nek̂s ‘dead person, death’, *wel- ‘die’, *mr̥tís ‘death’, *mr̥tóm ‘death’, *mr̥tós ‘dead, mortal’, *móros ‘death’, *mórtos ‘person, mortal, man’