senil russian

• ста́рческий

  senile

• дря́хлость

  decrepitude, senile infirmity

• ста́рчество

  old age, senility, dotage

  eldership, spiritual guidance by an elder, staretzdom

• полоу́мие

  feeble-mindedness, dementia, senility, dotage

• одряхле́вший

  decrepit, senile, superannuated, infirm

  dilapidated, ramshackle, worn out, rickety

Examples

• Он одряхле́л.

  He's gone senile.