"Sugar and pepper"
Generally, in Korea, 후추 means 'black pepper powder' rather than the peppercorns themselves.
雪 (눈 설): snow
糖 (엿 설): candy
so sugar in Korean (possibly also in Old Chinese) is literally "snow candy", i.e. snow like substance (because it is in powder form and white) that is candy. But why not just say candy (탕)? You see, in Chinese (and therefore in Sino-Korean words), there are too many homophones, so they need two characters to make the meaning less ambiguous.
胡 (턱밑살 호): recklessly, foolishly, wildly
椒 (산초나무 초): pepper, spices
What is interesting though, is that this second character seems to be referenced to as "초" in the dictionary.
Actually, I just looked at another dictionary written in Korean and it says that "호추" is actually a typo of "호초". Note that the second character here is "초", not "추".
So, anyway, since the separate definitions of the characters don't make sense together, I did some research and it seems "wild" here implies "foreign", since it (black pepper) wasn't native to China and had to be imported.
So that's it, black pepper in Korean has its roots way back from the time of Old Chinese, literally meaning "foreign pepper" or "pepper that is foreign to China".
Phew, that was a long one...