Degen.

Since ca. 1400, at first as degen, but also dege, dägen, tägen. Usually derived from Middle French dague, but the origin of the e-vocalism is unclear. An eastern dialectal *degue is possible, but apparently unattested, whereas Czech dýka is considered a borrowing from German. See French dague and Italian daga for more. Probably also related with the family of English dagger. From the 17th century, the sense “dagger” is restricted to Dolch, while Degen comes to refer to longer weapons, especially thrust-oriented dueling swords. By the 18th century it was used of any sword worn as part of a uniform.

From Middle High German dëgen, from Old High German dëgan. Cognate with Dutch degen, English thane, Icelandic þegn, Ancient Greek τέκνον (téknon). The word had become archaic by 1500, but was revived in poetic style since the later 18th century. This use may be a learned borrowing from Middle High German as there appear to be no attestations between ca. 1650 and 1750.