senior citizen
US /ˌsiː.njɚ ˈsɪt.ɪ.zən/
UK /ˌsiː.njɚ ˈsɪt.ɪ.zən/

1.
an elderly person, especially one who is retired and receiving a pension
:
•
The museum offers discounts for senior citizens.
•
Many senior citizens enjoy community activities.
an elderly person, especially one who is retired and receiving a pension