The characters for 점심 (點心) mean something like:
點 - 'point' or 'dot'
心 - 'heart'
Those characters have other meanings too, but I can't see from any of them how the characters come to make a word that means 'lunch'?
This is perhaps better asked at Chinese StackExchange, but from what I can gather, it is a slang word that first appeared in the Tang Dynasty. E.g.:
夫人 (someone's wife) said to her younger brother: "I haven't finished doing my makeup, and am not ready to dine, you can 點心."
My interpretation is that 點 means something similar to light up/excite, e.g. 點火/점화 (to ignite something) or 點香 (to light/burn incense), so 點心 means to light up the heart -> satisfy one's cravings.
Note that in Chinese, 點心 means snack, and is the word used for the tapas-like food in the Cantonese Yum Cha tradition Dim Sum.
점심 (點心 =putting a point in heart)
1.하루 중에 해가 가장 높이 떠 있는, 정오부터 반나절쯤까지의 동안. from 12 to 1 pm.
- 끼니로 먹는 음식. 또는 끼니를 먹는 일. food or eating food.
추가 설명 additional explanation :
동양 사상에는 아침은 제대로 먹고 점심 저녁은 가볍게 서양 사상에는 아침과 점심은 가볍게
저녁은 만찬이라해서 푸짐하게 먹는 습관이 있습니다.
In eastern philosophy we eat breakfast enough but lunch and supper a little.
But in western, we eat breakfast and lunch a little but supper enough, since it is a feast.
동양에서나 서양에서나 점심은 가볍게 먹는 습관을 가졌습니다.
That is, in both, lunch is to eat a little.
그래서 생겨난 말이 점심, 즉 점을 찍듯이 가볍게
먹는 음식이라는 뜻으로 사용하는 말이 되었답니다.
Therefor, we use 점심 for a word whose means eating a little like putting a point.