This is the 15531st most frequent Polish word.
starszego
"Starszego" means "of the elder" or "of the older" in English.
The word 'starszego' here is the masculine singular accusative form of the adjective 'starszy,' used to describe the noun 'mężczyznę' (man).
Widzę starszego mężczyznę stojącego w parku.
I see an older man standing in the park.
In this sentence, 'starszego' functions as the masculine singular genitive form of 'starszy,' modifying 'brata' (brother).
Ta książka należy do starszego brata.
This book belongs to the elder brother.
Here, 'starszemu' is the masculine singular dative form of 'starszy,' paired with 'sąsiadowi' (neighbor).