wrong: the term "devil dog" was originally coined by the Germans using "Teufel Hunden" allegedly meaning Devil Dog in German; its a motivational nickname for a U.S. Marine.
The exact origin of the term is unknown. According to tradition in the United States Marine Corps, it was given by German soldiers to U.S. Marines who fought in the Belleau Wood in 1918. This was reported by American media at the time; however, no evidence has been found of this usage in German records of the time.
The actual spelling, "Teufel Hunden", is not a correct spelling in German. The correct German spelling is Teufelshunde.
Either way much respect to all service men and women. Whenever I can thank them openly I will. hoo-rah I love the Marine Corp