This is the 18878th most frequent Korean word.
심장
Heart.
In this sentence, 심장 refers to the physical organ within the body responsible for pumping blood, indicating its physiological function.
그는 심장이 빠르게 뛰고 있었다.
His heart was beating rapidly.
Here, 심장 metaphorically signifies the emotional intensity or response to a stressful or thrilling event.
심장이 멈출 듯한 긴장이 느껴졌다.
I felt a tension as if my heart would stop.
In this case, 심장 is used figuratively to represent the emotional core or feelings of a person.