3 Words in Running Man 319(Running Man Go)
As you can see in the word, it means "after the end". Usually, it means your emotion, feeling, sometimes action after the end. It is usually used in negative sense.
Suppose that you did something wrong to your friend. You realized it and apologized for that. However, she doesn't forget it and sometimes tell you when you did something wrong again. In that case, we use "뒤끝 있다" to describe her.
그렇게 뒤끝 있는 사람인지 몰랐다.
I didn't know that she bears grudges.
그냥 뒤끝 없이 잘 헤어졌어.
We ended up our relation without any grudges.
If you are proud of something, it is 뿌듯하다 in Korean.
Then, some of you might have wondered the difference between 뿌듯하다 and 자랑스럽다. 뿌듯하다 emphasizes the great feeling you got. That's all. So, both of them are usually interchangeable.
이번 일을 성공적으로 마치게 되어서 무척 뿌듯했다.
I felt really great because I could finish it successfully.
나는 내 아들을 생각할 때마다 무척 뿌듯하다.
Whenever I think of my son, I am really proud of him.
비무장지대 is demilitaried zone, a.k.a. DMZ. South Korea is divided nation and the Korean War isn't ended. South and North Korea just stopped fighting temporarily.
Because of that, there is DMZ between North and South Korea. It's a zone 2km each from the MDL(Military Demarcation Line, simply it's a border between South and North Korea).
As there is no army in DMZ, there are many hart-to-see animals and plants in there. Sadly, there are also a lot of mine(not a mine for minerals, weapon)s.
In the screenshot above, 석진 moved out to somewhere without any enemy or friend. So, they used the word 비무장지대.
민간인은 비무장지대에 들어올 수 없다.
Civilians cannot enter DMZ.
군 생활 절반 정도를 비무장지대에서 보냈다.
I've spent almost half of my army days in DMZ.
(Actually, I really did.)