Dictionary

(with the, invariable plural only) People who are old; old beings; the older generation, taken as a group.

Example: A civilised society should always look after the old in the community.

(in combination) One of a specified age.

Example: when he was an eight-year-old ; a 62-year-old should

A person older than oneself, especially an adult in relation to a teenager.

(most often plural) One's parents.

Example: I had to sneak out to meet my girlfriend and tell the olds I was going to the library.

Of an object, concept, relationship, etc., having existed for a relatively long period of time.

Example: an old abandoned building;  an old friend

Having been used and thus no longer new or unused.

Example: I find that an old toothbrush is good to clean the keyboard with.

Having existed or lived for the specified time.

Example: How old are they? She’s five years old and he's seven. We also have a young teen and a two-year-old child.

(heading) Of an earlier time.