O.E. wrað, "angry" (lit. "tormented, twisted), from P.Gmc. *wraithaz (cf. O.Fris. wreth "evil," O.S. wred, M.Du. wret, Du. wreed "cruel," O.H.G. reid, O.N. reiðr "angry, offended"), from PIE *wreit- "to turn" (see wreath). Rare or obs. from early 16c. to mid-19c.,
but somewhat revived since, esp. in dignified writing, or this exchange:
Secretary: "The Dean is furious. He's waxing wroth." Quincy Adams Wagstaf [Groucho]: "Is Roth out there too? Tell Roth to wax the Dean for a while." ["Horse Feathers," 1932]