Find the word definition

The Collaborative International Dictionary
On the warpath

Warpath \War"path`\, n. The route taken by a party of Indians going on a warlike expedition.
--Schoolcraft.

On the warpath, on a hostile expedition; hence, colloquially, about to attack a person or measure.

Wiktionary
on the warpath

a. (context idiomatic English) Very angry or upset.

Wikipedia
On the Warpath

"On The Warpath" is a popular instrumental tune composed by Raymond A. Browne in 1904. "On The Warpath" was the first American popular music to incorporate a repeating tom-tom effect in the score.