feud, formalized private warfare, especially between family groups. The blood feud (see vendetta) is characteristic of those societies in which a strong central government either has not arisen or has decayed. In modern times the feud, outlawed in most countries, has persisted where public justice cannot be easily enforced and private means are a simpler recourse. A famous example is the 19th-century feud of the Hatfields and McCoys in the mountain regions of the southern United States. The frontier in U.S. history was also characterized by private justice and the feud.
See Waller, A. L., Feud: Hatfields, McCoys, and Social Change in Appalachia, 1860–1900 (1988).