Feargal is a slur used to describe Blacks in a derogatory way. Short for Feargal Sharkey (a UK Pop singer from late 70's and 80's) which rhymes with Darkie.
The word Feargal is a racial slur that has been used historically to degrade and dehumanize blacks. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to blacks. If you are unsure about whether or not it is appropriate to use the word Feargal, it is best to err on the side of caution and avoid using it in any situation.