Definition of long knife in US English:

long knife


  • 1"treachery (also plot, treason) of the long knives": a legendary massacre of the Britons by the Saxons under Hengist in the 5th cent.

  • 2"night of the long knives": (among Nazis) violent action against opponents, especially the arrest and killing of numerous prominent rivals (notably Ernst Röhm and other leaders of the Sturmabteilung) by the Nazi leadership, 30 June–2 July 1934; hence used allusively of any similar decisive or ruthless dealings by leaders with associates or staff.

  • 3Figurative or in figurative contexts, denoting the ruthless removal of unwanted associates or employees.

  • 4North American. Frequently in plural and with capital initials. (A translation of) a name given by North American Indians to a white settler, especially of Virginia, or a white soldier; (sometimes specifically) a citizen of the United States as opposed to a Canadian or other British subject in North America. Compare Big Knife. Now historical.


Early 17th century; earliest use found in Meredith Hanmer (1543–1604), Church of England and Church of Ireland clergyman and historian. From long + knife.


long knife

/ˌlɒŋ ˈnʌɪf/