Correct spelling for the English word "goaffin" is [ɡˈə͡ʊfɪn], [ɡˈəʊfɪn], [ɡ_ˈəʊ_f_ɪ_n] (IPA phonetic alphabet).
The refuse thrown back into the mine, after the removal of the coal, to help to support the roof.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.