This is the 1836th most frequent Polish word.
chinach
"Chinach" means "China" in the locative case in Polish.
The word 'Chinach' is the locative case of 'Chiny' (China) and is used here to indicate location, implying the speaker has been physically present in China.
Byłem kiedyś w Chinach.
I have been to China once.
'Chinach' again is the locative case of 'Chiny', referring to the context of the country China as the topic of interest.
Wszystko w Chinach jest bardzo interesujące.
Everything in China is very interesting.
The word 'Chinach' is used to convey interest specifically in the historical and cultural aspects within the location of China.