An Oldsmobile.
"The olds gathered in the living room to celebrate their anniversary."
parents
A surname.
"The Olds family gathered at their annual reunion in Michigan."
Olds is a colloquial shortening of the phrase "old folks," which was first used to refer to elderly people as early as the mid-19th century. The term functions similarly to other affectionate or informal groupings like "old man" but specifically emphasizes plural elders rather than an individual senior citizen.