The term 'Hatfield Foe' refers to the Hatfield-McCoy feud, a long-standing dispute between two families in the Appalachian Mountains of West Virginia and Kentucky. The feud began in the late 19th century and lasted for decades. The Hatfield family was led by William Anderson 'Devil Anse' Hatfield, while the McCoy family was led by Randolph 'Ole Ran'l' McCoy. The feud was characterized by violence and revenge, and it became a symbol of the deep divisions between the two families. The crossword solution for the term 'Hatfield Foe' is 'MCCOY, ' referring to the McCoy family.