warpath

war +‎ path

warpath (plural warpaths)

1. (historical) The route taken by a party of Native Americans going on a warlike expedition.
   • Henry R. Schoolcraft, The Myth of Hiawatha, and Other Oral Legends

     He went often to visit the spot where the women had buried her, and sat musing there, when, it was thought, by some of his friends, he would have done better to try to amuse himself in the chase, or by diverting his thoughts in the war-path.

2. (figuratively) A course of action that leads to battle or hostility.

This word is most often used in the phrase “on the warpath”.