There are several synonyms that can be used for the term "old-age pensioners". Some of them are senior citizens, retired persons, elderly people, retirees, golden agers, and elders. Each of these terms are used to describe people who have reached the retirement age and are receiving pension or other benefits from the government or other organizations.
The term "senior citizens" is a more general term that can include anyone over the age of 60 or 65, whereas "old-age pensioners" specifically refers to those who are receiving pensions. "Retirees" is another common term used to describe those who have left the workforce and are no longer employed, while "golden agers" is a more positive and upbeat term that emphasizes the value and experiences of older individuals.
Overall, using a variety of synonyms helps to avoid repetition and also acknowledges the diversity and richness of the older population.