This is the 951st most frequent Korean word.
충남
Chungnam; short for Chungcheongnam-do, a province in South Korea.
Here, '충남' specifies the location where the event took place within the province of Chungcheongnam-do.
충남에서 열린 행사에 참가했어요.
I participated in an event held in Chungnam.
In this sentence, '충남' refers to a geographical location, specifically the province Chungcheongnam-do.
충남은 한국의 한 도입니다.
Chungnam is a province in South Korea.
In this context, '충남' is used to indicate the origin of a person, highlighting that they are from Chungcheongnam-do province.