Kay H. answered 10/01/19
Master's Degree in Teaching with 17 years Teaching Experience
These words are one of the uniquely developed features in Korean language.
Koreans call them 의태어. They describe something or someone’s movement, shape or action.
In a similar way, there are the words describing sound. We call these 의성어: 부스럭 부스럭(bustling noise), 쾅(thumping noise), etc.