The crossword solution for the term 'ADD YEARS TO ONE'S LIFE' is AGE, which is a three-letter word. AGE is a measure of time that is used to describe the length of a person's life. It is often used as a metaphor for wisdom and experience. Adding years to one's life can refer to extending the amount of time a person lives, or it can refer to making the most of the time one has by living life to its fullest.