This is the 3245th most frequent Polish word.
starszych
"Starszych" means "older" or "elders" in English, depending on context.
Here, 'starszych' is used as an adjective meaning 'older', describing 'ludzi' (people) in the Genitive plural case.
Starszych ludzi należy szanować.
Older people should be respected.
Here, 'starszych' refers to 'elders' and is used substantively, functioning as a noun in the Genitive plural case.
Spotkałem się z opiniami starszych.
I encountered the opinions of the elders.
In this sentence, 'starszych' describes 'czytelników' (readers) in the Genitive plural case, specifying a target group.