An Etymological Dictionary of the German Language/Annotated/Degen
Degen (1.), masculine, ‘valiant warrior’; it is not etymologically a sort of figurative sense of Degen (2.), though the tendency of Modern High German is to regard it thus, in such expressions as alter Haudegen, ‘a practised swordsman,’ &c. While Degen, ‘sword,’ first appears in the 15th century, Degen, ‘hero,’ is an Old Teutonic word, which is wanting in Gothic (*þigns) only. Compare Old High German dëgan, Anglo-Saxon þëgn, ‘retainer, attendant,’ English thane (from þegn); Middle High German dëgen, ‘hero.’ There is to phonetic difficulty in connecting these cognates (Gothic þigna-, from teknó-), as is usually done, with Greek τέκνον, ‘child’; the difference in sense may be paralleled by Anglo-Saxon magu, ‘boy, son, servant, man.’ But since þëgn was already an established technical term in the Old Teutonic system, we must in preference regard ‘vassal’ as the primary sense of the word. We have too in Gothic þius (stem þiwa-) for þigwá-, ‘servant, attendant’ (Anglo-Saxon þeó, þeów, Old High German diu; see Dirne and dienen), a more suitable connecting link. Moreover, þëgn, Degen, would, if cognate with τέκνον, be related to τίκτω, ‘to give birth to,’ τοκεύς, ‘begetter,’ τόκος, ‘birth,’ and Sanscrit takman, ‘child.’
Degen (2.), masculine, ‘sword,’ first occurs in late Middle High German see Degen (1.); from French dague, ‘dirk.’