This is the 1007th most frequent Japanese word.
関西
Kansai: A region in western Japan, including cities like Osaka, Kyoto, and Kobe.
Here, '関西' refers to a geographical area in Japan.
彼は関西地方に住んでいます。
He lives in the Kansai region.
In this instance, '関西' describes the linguistic and cultural characteristic associated with the Kansai area, specifically its dialect.
関西弁はとてもユニークな方言だと思います。
I think Kansai dialect is a very unique dialect.
'関西' is used to indicate a specific location where an event, such as a festival, takes place.