Muck is a slur used to describe Eskimos in a derogatory way. Short for Eskimuck, due to the problems the Eskimo have pronouncing the English language.
The word Muck is a racial slur that has been used historically to degrade and dehumanize eskimos. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to eskimos. If you are unsure about whether or not it is appropriate to use the word Muck, it is best to err on the side of caution and avoid using it in any situation.