In Korea, there is a word expressing an emotion that people use with great frequency, though it doesn't translate well into English: “seounhada.”

This term, used interchangeably with “seopseophada,” captures a combination of feelings: hurt, disappointment, sadness or a sense of being mistreated, ignored or even offended. It can be a combination of all or any of those feelings, but subtle and not too intense. And here's the kicker — these feelings are often not openly expressed; if they are, it’s usually behind the back of the person who caused them. Very nonconfrontational.

To some who are not native Korean speakers, the concept might initially be perplexing.

“Every language has one word that is often used and can have a deeper meaning, which is what I believe ‘seounhada’ is. It’s more than just sadness, and at first it wasn’t easy to understand,” said Adrianna Anastasiades, 31, a London native who has lived in Korea for three years.

“To be honest, it’s not a word I use often (when I speak Korean). When I feel sad, I usually say ‘seulpeuda,’ which means 'sad' in Korean,” she added.

For those who have grown up in South Korea, however, feeling seounhada is part of daily life, with it arising in all kinds of situations.

Kang Si-eun, in her 40s, a mother whose son started middle school this year, said she felt this emotion toward her son.

“My son used to follow me everywhere, holding my hand,” she said. “Now he walks behind me and says, ‘I don’t want my friends to see me with you, they’ll call me a mama’s boy.’”

Kang knew better and didn’t make a big deal out of it. “It’s just puberty. He’ll come around,” was the rational mom's perspective, yet inside, the feelings of hurt lingered.

There’s also Park Hae-in, a university student whose two best friends started dating each other. Naturally, their trio became reduced to a duo, leaving Park to experience this mixture of feelings.

“I understand things change,” she said. “But still.”

And did she mention this to them? Of course not.

“I didn’t want to seem like I was interfering. Besides, what would change even if I did?”

Then there's Kim Jae-sik, in his 30s, who felt this emotion when his girlfriend went to a restaurant they’d promised to visit together — for the first time — with someone else.

“She said she only had anju (snacks served with alcohol), leaving the meal menu for when we go together,” Kim said. “She promised we’d go together, and I said ‘okay,’ but... I still felt a bit ‘seounhae.’”

This isn't just a fleeting emotion either — sometimes it can stick around for decades.

Take Baek, 60, who still remembers feeling it 34 years ago, right after giving birth.

She, her husband and the newborn moved in with her mother-in-law while she recovered and to take care of the baby, but instead of getting equal rest, her husband was told to sleep in a separate room, while the two women took care of the baby through the night.

“My mother-in-law said it wouldn't be right for him to be tired because he had to work. I’ll never forget how that made me feel,” Baek said, conveying her hurt about her mother-in-law valuing her husband more than her.

The tricky part is, that the person who caused the emotion often has no clue they’ve done anything wrong. So when it eventually comes up — if it ever does — it can feel like the emotion just appeared out of nowhere.

Some psychology experts suggest that dealing with these subtle hurt feelings — ones that people hate to express openly but can’t quite get over — could be unique to Korea's context, reflecting a specific approach to personal relationships.

Han Seong-yeul, emeritus professor of psychology at Korea University, explains in his book, "Korean Culture and Suicide," (direct translation) that Koreans long for “il-sim-dong-che,” which directly translates to being of “one mind, one body" -- the fantasy of complete harmony in relationships with others.

“In an 'il-sim-dong-chae' relationship, you are already 'one,' so you don't feel the need to convey your thoughts or feelings to the other person,” he writes, “A relationship where you have to explain your feelings is not ideal (to Koreans).”

Psychologist Kim Tae-hyung echoed this in his book about the psychology of Koreans, saying that in their perceived ideal relationship -- which he calls a "we relationship" -- people should know what the other party is feeling and thinking without ever being told.

"Ideal relationships are not ones in which I have to explain my feelings to the other person. For this reason, Koreans consider the moment when the other person does not understand their feelings as a red flag," Kim said.

Kim explained that this is when Koreans typically feel the emotions of seopseophada or seounhada.

Im Myung-ho, a psychology professor at Dankook University, in a phone interview with The Korea Herald, pointed out the potential harm of this emotion, given that it arises from unvoiced expectations of others that are practically impossible to meet.

"It cannot be considered healthy," Im added. "Because from a psychological perspective, there is also a sense of (the feeling of seounhada having the expectation) of compensation behind it: I've done something for you, so you should do something for me."

He explained that this expectation to be compensated emotionally is based on the person who feels seounhada having an inferiority complex.

“So when such emotions arise, they should be discussed to resolve them," Im stressed.