Euphemism for "old" (person) [closed]

One such idiom is along in years:

Definition: Someone who is old, growing old, or elderly.

The idiomatic expression along in years refers to someone who is old or elderly. Native English speakers use it as a euphemism to illustrate that someone is growing older.

When used in this context, the verb getting often precedes the phrase.
Writing Explained

This idiom can be used to describe people or animals.