This is the 3708th most frequent Polish word.
kościelnego
"Kościelnego" means "church-related" or "pertaining to the church" in English.
The word 'kościelnego' here qualifies 'zdania', indicating something relating to the church or religious context.
On był kościelnego zdania.
He held a church-related opinion.
Here 'kościelnego' refers to a person specifically acting in a role associated with church support, like a sexton.
Widzieliśmy kościelnego w czasie mszy.
We saw the church servant during the mass.
In this sentence, 'kościelnego' describes the style or characteristic of the interior, which is related to the church or religious features.