A few days ago, there was an incident injuring three people with a knife on a subway. A 37-year-old woman speaking on the phone has injured them because someone called her 'ajumma'. The accused said she resented the word 'ajumma'.
In Korean, there is a unique word referring to a middle-aged woman at the age of 50 or more who is unrelated to the speaker. It is 'ajumma'. 'Ajumeoni'(아주머니) is a more respectful word than 'ajumma'. When you think of traveling to Korea or living for a certain period of time in Korea, it is necessary for you to know about the social background reflecting on the word 'ajumma'.
'Ajumma' is indicated for aged Korean females over 50. We don't know the official age range of 'ajumma'. A respectful word, 'ajumeoni' would be widely accepted. If you enter a Korean restaurant, not a fast food restaurant, you could easily meet 'ajumeuni' working as a server. As you sit down at the table, they come and ask "May I take your order?" then you can order. When you need something else like more water or an extra plate, you can call them 'ajumeoni' or 'here'.
'Ajumeoni' is only used to call middle-aged women. It is not suitable to call young females at the age of 30 or less. 'Ajumeoni' to them could hurt their feelings. When needed to call them, just say 'Excuse me' or 'here'. 'Agassi' or 아가씨 would be a comparative word with 'ajumeoni' that can be used for the young female. Nowadays, people hardly use 'agassi' but sometimes, they use this word to the young server at a restaurant instead of 'here'.