When to use middle-aged woman in Korean
Korean: 아줌마[ a-jum-ma ]

When to use it
아줌마 means a middle-aged woman, often a married woman. People also use it for a woman like a shop lady or a neighbor. It is common in daily life, but it can sound less polite when you say it directly to someone, so be careful.
Example sentences
우리 옆집 아줌마는 아주 친절해요.
The woman next door is very kind.
가게 아줌마가 사과를 주셨어요.
The shop lady gave me an apple.
버스에서 아줌마가 자리에 앉았어요.
A middle-aged woman sat down on the bus.
엄마는 시장 아줌마와 이야기해요.
Mom talks with the lady at the market.
학교 앞 문구점 아줌마를 알아요.
I know the lady at the stationery shop in front of the school.
길에서 아줌마에게 역을 물어봤어요.
I asked a middle-aged woman for the station on the street.