Adjective
Foully.
Source: Webster's dictionaryIt is a foule byrd that fyleth his owne nest. John Heywood
Na he that ay has levyt fre May nocht knaw weill the propyrte The angyr na the wrechyt dome That is couplyt to foule thyrldome, Bot gyff he had assayit it. Than all perquer he suld it wyt, And suld think fredome mar to prys Than all the gold in warld that is. John Barbour
The foule Toade hath a faire stone in his head. English Proverb