컵 means ‘cup’ and 버스 means ‘bus’. These two are really similar to the English words because they are ‘loan words’, therefore they sound really similar and their meaning is the same, of course. See the other words from 30.03.2019 (they are not ‘loan words’).
천둥 means ‘thunder’ and, to me, it sounds interesting.
천둥 is one of the 5 words I listed on one of my pages from the ‘Words of the day’ category. Find out the rest of the words here and see if you already know them!